<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:c06944a5-a3c4-489d-bc7f-c3f2173aa1ee,g:182e2ed4-e853-4277-9900-06c02b12aee4-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.quakerchem.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY" xlink:type="simple" xlink:href="kwr-20241231.xsd#CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_6d68d0eb-ab8b-4261-a325-7f028ff731db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_3a699acd-d048-4e00-b8fb-65e30d51a0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6d68d0eb-ab8b-4261-a325-7f028ff731db" xlink:to="loc_us-gaap_StatementTable_3a699acd-d048-4e00-b8fb-65e30d51a0dd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_eb619afb-98f6-4065-91fa-5b110015d26e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_3a699acd-d048-4e00-b8fb-65e30d51a0dd" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_eb619afb-98f6-4065-91fa-5b110015d26e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_eb619afb-98f6-4065-91fa-5b110015d26e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_eb619afb-98f6-4065-91fa-5b110015d26e" xlink:to="loc_us-gaap_EquityComponentDomain_eb619afb-98f6-4065-91fa-5b110015d26e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_eb619afb-98f6-4065-91fa-5b110015d26e" xlink:to="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_c5ca2d04-e39a-4d86-8932-feb89e96d365" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:to="loc_us-gaap_CommonStockMember_c5ca2d04-e39a-4d86-8932-feb89e96d365" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_0815d8d3-d020-4dc5-a1a9-f4244616c5c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_0815d8d3-d020-4dc5-a1a9-f4244616c5c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_15a99f40-47e4-4d9a-96fd-666838e811a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:to="loc_us-gaap_RetainedEarningsMember_15a99f40-47e4-4d9a-96fd-666838e811a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_9d6ed6af-60ba-4365-8934-e08f19e88b48" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_9d6ed6af-60ba-4365-8934-e08f19e88b48" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_68c2483c-1460-4349-9781-96fc82d7439f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_47813b1f-1292-4823-848c-6728b847767d" xlink:to="loc_us-gaap_NoncontrollingInterestMember_68c2483c-1460-4349-9781-96fc82d7439f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6d68d0eb-ab8b-4261-a325-7f028ff731db" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_33063695-4786-4aad-a626-b534bd2af35a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_33063695-4786-4aad-a626-b534bd2af35a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_b491bffa-ab8d-4c2c-be04-1fbd86cb2bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_ProfitLoss_b491bffa-ab8d-4c2c-be04-1fbd86cb2bc2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_be331c35-e905-4cb5-84a0-e473c2c0ee81" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_be331c35-e905-4cb5-84a0-e473c2c0ee81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_985f3ac4-536d-447b-98a3-6bfd4015e0e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_DividendsCommonStock_985f3ac4-536d-447b-98a3-6bfd4015e0e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_4e78031e-f029-4d61-a978-121bacb0b86d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_4e78031e-f029-4d61-a978-121bacb0b86d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_09aacea9-af2c-49d2-b2c4-82728166de5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_09aacea9-af2c-49d2-b2c4-82728166de5d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross_6ea90d40-be22-48e2-a964-9fe9878d0f70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_8a9d5c11-46bb-41b8-92d8-6334ebc44b7a" xlink:to="loc_us-gaap_StockGrantedDuringPeriodValueSharebasedCompensationGross_6ea90d40-be22-48e2-a964-9fe9878d0f70" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e5c573d8-8a4e-4703-aef3-ee7519997a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesHyperinflationaryaccountingDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BasisofPresentationandSignificantAccountingPoliciesHyperinflationaryaccountingDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesHyperinflationaryaccountingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_1a45219b-3f3d-4c42-93a7-e8c8411912f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_661952a4-021e-49fc-8c27-c7b174ec32c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1a45219b-3f3d-4c42-93a7-e8c8411912f9" xlink:to="loc_us-gaap_ConcentrationRiskTable_661952a4-021e-49fc-8c27-c7b174ec32c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_2b9d8bf5-b09b-4bba-b5ce-b11a13696404" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_661952a4-021e-49fc-8c27-c7b174ec32c3" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_2b9d8bf5-b09b-4bba-b5ce-b11a13696404" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_2b9d8bf5-b09b-4bba-b5ce-b11a13696404_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_2b9d8bf5-b09b-4bba-b5ce-b11a13696404" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_2b9d8bf5-b09b-4bba-b5ce-b11a13696404_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7569f925-b1ce-4884-9a2b-a15c547f7b71" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_2b9d8bf5-b09b-4bba-b5ce-b11a13696404" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7569f925-b1ce-4884-9a2b-a15c547f7b71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsTotalMember_67c6426c-0fc6-453d-8923-53f033fe7ff9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsTotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7569f925-b1ce-4884-9a2b-a15c547f7b71" xlink:to="loc_us-gaap_AssetsTotalMember_67c6426c-0fc6-453d-8923-53f033fe7ff9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_dfc2f106-d7b9-4d59-9cbc-312fff7aa9aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_7569f925-b1ce-4884-9a2b-a15c547f7b71" xlink:to="loc_us-gaap_SalesRevenueNetMember_dfc2f106-d7b9-4d59-9cbc-312fff7aa9aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_7d9732ba-7271-4e66-8e51-6e58a4c353f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_661952a4-021e-49fc-8c27-c7b174ec32c3" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_7d9732ba-7271-4e66-8e51-6e58a4c353f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_7d9732ba-7271-4e66-8e51-6e58a4c353f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_7d9732ba-7271-4e66-8e51-6e58a4c353f9" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_7d9732ba-7271-4e66-8e51-6e58a4c353f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_43577667-7eac-4821-a8cc-0a61a322446d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_7d9732ba-7271-4e66-8e51-6e58a4c353f9" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_43577667-7eac-4821-a8cc-0a61a322446d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_dc1af039-1828-4c11-9eb3-2c154568bc21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_43577667-7eac-4821-a8cc-0a61a322446d" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_dc1af039-1828-4c11-9eb3-2c154568bc21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_99c8586f-c4f0-428d-ad55-4bb740f6e538" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_661952a4-021e-49fc-8c27-c7b174ec32c3" xlink:to="loc_srt_ConsolidatedEntitiesAxis_99c8586f-c4f0-428d-ad55-4bb740f6e538" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_99c8586f-c4f0-428d-ad55-4bb740f6e538_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_99c8586f-c4f0-428d-ad55-4bb740f6e538" xlink:to="loc_srt_ConsolidatedEntitiesDomain_99c8586f-c4f0-428d-ad55-4bb740f6e538_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_14bf1301-4bec-4d7e-91c2-fb378c424669" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_99c8586f-c4f0-428d-ad55-4bb740f6e538" xlink:to="loc_srt_ConsolidatedEntitiesDomain_14bf1301-4bec-4d7e-91c2-fb378c424669" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_1a3bfc55-199c-4d33-b960-3e69303ca896" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_14bf1301-4bec-4d7e-91c2-fb378c424669" xlink:to="loc_srt_SubsidiariesMember_1a3bfc55-199c-4d33-b960-3e69303ca896" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_InflationaryPercentage_23771cfe-a5e0-4648-bdc0-1f1f9d13fa5b" xlink:href="kwr-20241231.xsd#kwr_InflationaryPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1a45219b-3f3d-4c42-93a7-e8c8411912f9" xlink:to="loc_kwr_InflationaryPercentage_23771cfe-a5e0-4648-bdc0-1f1f9d13fa5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_d6769a34-f225-4081-9a4d-7bdfeccccfae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1a45219b-3f3d-4c42-93a7-e8c8411912f9" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_d6769a34-f225-4081-9a4d-7bdfeccccfae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmountRecognizedInIncomeDueToInflationaryAccounting_fa7bc55c-ea6a-4f93-85d0-5f3ed6802239" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmountRecognizedInIncomeDueToInflationaryAccounting"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_1a45219b-3f3d-4c42-93a7-e8c8411912f9" xlink:to="loc_us-gaap_AmountRecognizedInIncomeDueToInflationaryAccounting_fa7bc55c-ea6a-4f93-85d0-5f3ed6802239" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BasisofPresentationandSignificantAccountingPoliciesPropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesPropertyPlantandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_a5a5891c-148d-402f-8cf4-8916fd574327" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2492f031-955c-4407-a5ae-fc8267ada52a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_a5a5891c-148d-402f-8cf4-8916fd574327" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2492f031-955c-4407-a5ae-fc8267ada52a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_92129f1c-7e39-4d49-b15c-383b0f645cdb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2492f031-955c-4407-a5ae-fc8267ada52a" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_92129f1c-7e39-4d49-b15c-383b0f645cdb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_92129f1c-7e39-4d49-b15c-383b0f645cdb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_92129f1c-7e39-4d49-b15c-383b0f645cdb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_92129f1c-7e39-4d49-b15c-383b0f645cdb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_963b1f09-598c-425c-9372-2db63cec6c22" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_92129f1c-7e39-4d49-b15c-383b0f645cdb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_963b1f09-598c-425c-9372-2db63cec6c22" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_c1e9f126-1d0b-4f5c-8b71-98d77155d183" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_963b1f09-598c-425c-9372-2db63cec6c22" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_c1e9f126-1d0b-4f5c-8b71-98d77155d183" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_941cb9bf-9f92-483d-97b3-a3fa34607def" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_963b1f09-598c-425c-9372-2db63cec6c22" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_941cb9bf-9f92-483d-97b3-a3fa34607def" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_8aec0563-bd3f-46ec-83db-e68d5ea3c014" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_2492f031-955c-4407-a5ae-fc8267ada52a" xlink:to="loc_srt_RangeAxis_8aec0563-bd3f-46ec-83db-e68d5ea3c014" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8aec0563-bd3f-46ec-83db-e68d5ea3c014_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_8aec0563-bd3f-46ec-83db-e68d5ea3c014" xlink:to="loc_srt_RangeMember_8aec0563-bd3f-46ec-83db-e68d5ea3c014_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_108873a7-ebe5-42f9-9e9c-f0ce0beef18a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_8aec0563-bd3f-46ec-83db-e68d5ea3c014" xlink:to="loc_srt_RangeMember_108873a7-ebe5-42f9-9e9c-f0ce0beef18a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_89d07c9f-bac1-4672-9b06-da25a4c41e72" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_108873a7-ebe5-42f9-9e9c-f0ce0beef18a" xlink:to="loc_srt_MinimumMember_89d07c9f-bac1-4672-9b06-da25a4c41e72" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c6be0a58-cbfc-4c08-9854-2f1d25c76b2f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_108873a7-ebe5-42f9-9e9c-f0ce0beef18a" xlink:to="loc_srt_MaximumMember_c6be0a58-cbfc-4c08-9854-2f1d25c76b2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_f0cc9d5d-949c-4d75-b3f5-2867d793111c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_a5a5891c-148d-402f-8cf4-8916fd574327" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_f0cc9d5d-949c-4d75-b3f5-2867d793111c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesCapitalizedsoftwareDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BasisofPresentationandSignificantAccountingPoliciesCapitalizedsoftwareDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesCapitalizedsoftwareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2d91c481-1dd5-4bd2-a321-4a140da2216b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bdf6ef78-dd95-4ac8-9fbe-8397b0d665bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2d91c481-1dd5-4bd2-a321-4a140da2216b" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bdf6ef78-dd95-4ac8-9fbe-8397b0d665bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b4f1baff-266f-402c-a797-faea54dcae3f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bdf6ef78-dd95-4ac8-9fbe-8397b0d665bb" xlink:to="loc_srt_RangeAxis_b4f1baff-266f-402c-a797-faea54dcae3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b4f1baff-266f-402c-a797-faea54dcae3f_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b4f1baff-266f-402c-a797-faea54dcae3f" xlink:to="loc_srt_RangeMember_b4f1baff-266f-402c-a797-faea54dcae3f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_051c1a6a-bf28-4641-8a41-901e362c6bc5" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b4f1baff-266f-402c-a797-faea54dcae3f" xlink:to="loc_srt_RangeMember_051c1a6a-bf28-4641-8a41-901e362c6bc5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_162f4525-f978-4d4b-a65a-51a6b5e3792b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_051c1a6a-bf28-4641-8a41-901e362c6bc5" xlink:to="loc_srt_MinimumMember_162f4525-f978-4d4b-a65a-51a6b5e3792b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_df365b07-b36f-4926-8f91-df0def21539a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_051c1a6a-bf28-4641-8a41-901e362c6bc5" xlink:to="loc_srt_MaximumMember_df365b07-b36f-4926-8f91-df0def21539a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d9511d75-7897-457f-90a4-dde79dc82ca8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_bdf6ef78-dd95-4ac8-9fbe-8397b0d665bb" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d9511d75-7897-457f-90a4-dde79dc82ca8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d9511d75-7897-457f-90a4-dde79dc82ca8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d9511d75-7897-457f-90a4-dde79dc82ca8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_d9511d75-7897-457f-90a4-dde79dc82ca8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0f7bcaaf-2d26-43c3-b600-6ed0a8326e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_d9511d75-7897-457f-90a4-dde79dc82ca8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0f7bcaaf-2d26-43c3-b600-6ed0a8326e9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareDevelopmentMember_0cb6f395-10dd-479d-b739-d0e04de5ef51" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SoftwareDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0f7bcaaf-2d26-43c3-b600-6ed0a8326e9c" xlink:to="loc_us-gaap_SoftwareDevelopmentMember_0cb6f395-10dd-479d-b739-d0e04de5ef51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_b7bb0eed-f84b-4fdf-974c-404672f67099" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2d91c481-1dd5-4bd2-a321-4a140da2216b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_b7bb0eed-f84b-4fdf-974c-404672f67099" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareNet_a71b7357-ba96-42b0-a07f-f24a6e157bad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CapitalizedComputerSoftwareNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_2d91c481-1dd5-4bd2-a321-4a140da2216b" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareNet_a71b7357-ba96-42b0-a07f-f24a6e157bad" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesIncometaxesanduncertaintaxpositionsDetails_1" xlink:type="simple" xlink:href="kwr-20241231.xsd#BasisofPresentationandSignificantAccountingPoliciesIncometaxesanduncertaintaxpositionsDetails_1"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesIncometaxesanduncertaintaxpositionsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_eaf35b4c-4873-4725-b25e-345e8770c3d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbbdbd0-ffa8-45b4-af2e-8e0dcf93ed81" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_eaf35b4c-4873-4725-b25e-345e8770c3d9" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbbdbd0-ffa8-45b4-af2e-8e0dcf93ed81" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_676bdb19-3c75-4ccc-85fd-82a3bae897ad" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_3dbbdbd0-ffa8-45b4-af2e-8e0dcf93ed81" xlink:to="loc_srt_RangeAxis_676bdb19-3c75-4ccc-85fd-82a3bae897ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_676bdb19-3c75-4ccc-85fd-82a3bae897ad_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_676bdb19-3c75-4ccc-85fd-82a3bae897ad" xlink:to="loc_srt_RangeMember_676bdb19-3c75-4ccc-85fd-82a3bae897ad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f2c0d67c-0d1c-42e9-a835-39441a074229" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_676bdb19-3c75-4ccc-85fd-82a3bae897ad" xlink:to="loc_srt_RangeMember_f2c0d67c-0d1c-42e9-a835-39441a074229" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_73963df9-cb78-47b8-a868-ff1f7b73303d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f2c0d67c-0d1c-42e9-a835-39441a074229" xlink:to="loc_srt_MinimumMember_73963df9-cb78-47b8-a868-ff1f7b73303d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c5b0ce71-45ee-47e7-9952-97bbcea79674" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_f2c0d67c-0d1c-42e9-a835-39441a074229" xlink:to="loc_srt_MaximumMember_c5b0ce71-45ee-47e7-9952-97bbcea79674" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_36772bf1-0532-4ca6-abef-14507a68bd5c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_eaf35b4c-4873-4725-b25e-345e8770c3d9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_36772bf1-0532-4ca6-abef-14507a68bd5c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesDerivativesDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BasisofPresentationandSignificantAccountingPoliciesDerivativesDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BasisofPresentationandSignificantAccountingPoliciesDerivativesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_fb800165-c8df-4431-b5f4-5b171412cf31" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_bf1ce326-25c8-4ae4-93ff-be61c976e1d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_fb800165-c8df-4431-b5f4-5b171412cf31" xlink:to="loc_us-gaap_DerivativeTable_bf1ce326-25c8-4ae4-93ff-be61c976e1d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_4608c740-d191-4ecd-9e02-27f7c047b28d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bf1ce326-25c8-4ae4-93ff-be61c976e1d3" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_4608c740-d191-4ecd-9e02-27f7c047b28d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_4608c740-d191-4ecd-9e02-27f7c047b28d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4608c740-d191-4ecd-9e02-27f7c047b28d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_4608c740-d191-4ecd-9e02-27f7c047b28d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_562f3f94-5429-43c2-b2b5-8e904d747a82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_4608c740-d191-4ecd-9e02-27f7c047b28d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_562f3f94-5429-43c2-b2b5-8e904d747a82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_c4b90675-a0d5-4cc8-93c1-62c8e0ee563a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_562f3f94-5429-43c2-b2b5-8e904d747a82" xlink:to="loc_us-gaap_InterestRateSwapMember_c4b90675-a0d5-4cc8-93c1-62c8e0ee563a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_1e940ea0-5fb4-488e-8559-23db6cc74b52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_fb800165-c8df-4431-b5f4-5b171412cf31" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_1e940ea0-5fb4-488e-8559-23db6cc74b52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_0a2ff8f8-12c2-4e66-b168-23bec716d0d6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_fb800165-c8df-4431-b5f4-5b171412cf31" xlink:to="loc_us-gaap_DerivativeTermOfContract_0a2ff8f8-12c2-4e66-b168-23bec716d0d6" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessCombinationsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessCombinationsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessCombinationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_17f68aab-33ca-471c-9710-1720bec79eb0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_17f68aab-33ca-471c-9710-1720bec79eb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_17f68aab-33ca-471c-9710-1720bec79eb0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_17f68aab-33ca-471c-9710-1720bec79eb0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_17f68aab-33ca-471c-9710-1720bec79eb0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_17f68aab-33ca-471c-9710-1720bec79eb0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_SutaiGroupMember_e234e01f-7e89-40bc-bd28-fe83cc821e7b" xlink:href="kwr-20241231.xsd#kwr_SutaiGroupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:to="loc_kwr_SutaiGroupMember_e234e01f-7e89-40bc-bd28-fe83cc821e7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_I.K.V.TribologieIKVTMember_3cd6abe0-b71d-4f67-b574-9ba8ec4de0b8" xlink:href="kwr-20241231.xsd#kwr_I.K.V.TribologieIKVTMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:to="loc_kwr_I.K.V.TribologieIKVTMember_3cd6abe0-b71d-4f67-b574-9ba8ec4de0b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_BusinessRelatedToPicklingAndRinsingProductsAndServicesMember_5ee5de3a-1433-475e-a17e-f5eb1078d00a" xlink:href="kwr-20241231.xsd#kwr_BusinessRelatedToPicklingAndRinsingProductsAndServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:to="loc_kwr_BusinessRelatedToPicklingAndRinsingProductsAndServicesMember_5ee5de3a-1433-475e-a17e-f5eb1078d00a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_BusinessProvidingPicklingInhibitorTechnologiesMember_1f509607-551f-408f-bafd-d3ec0b1c48c2" xlink:href="kwr-20241231.xsd#kwr_BusinessProvidingPicklingInhibitorTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:to="loc_kwr_BusinessProvidingPicklingInhibitorTechnologiesMember_1f509607-551f-408f-bafd-d3ec0b1c48c2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_CSIMember_04d4ef42-ce47-4195-8310-efa4aff6320c" xlink:href="kwr-20241231.xsd#kwr_CSIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7af2b5e9-b19e-49b0-b0f0-770f217138c0" xlink:to="loc_kwr_CSIMember_04d4ef42-ce47-4195-8310-efa4aff6320c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5500e4c7-fa26-4942-807b-ad8305e6c348" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5500e4c7-fa26-4942-807b-ad8305e6c348" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5500e4c7-fa26-4942-807b-ad8305e6c348_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5500e4c7-fa26-4942-807b-ad8305e6c348" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5500e4c7-fa26-4942-807b-ad8305e6c348_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5500e4c7-fa26-4942-807b-ad8305e6c348" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_82eb5cee-c53f-47b7-9745-ccc81ebf98eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:to="loc_us-gaap_CustomerRelationshipsMember_82eb5cee-c53f-47b7-9745-ccc81ebf98eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_98fff799-07d0-4ca8-9838-6261bec72f75" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_98fff799-07d0-4ca8-9838-6261bec72f75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_87364dcb-7e23-4427-8271-47788292d1e6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:to="loc_us-gaap_TrademarksMember_87364dcb-7e23-4427-8271-47788292d1e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ProductTechnologyMember_4d82057e-39fd-4f1b-a9c6-97cb85d9a7e3" xlink:href="kwr-20241231.xsd#kwr_ProductTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:to="loc_kwr_ProductTechnologyMember_4d82057e-39fd-4f1b-a9c6-97cb85d9a7e3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PatentedTechnologyMember_fda76f6d-32c6-435a-8a47-168597853bea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PatentedTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9155343f-3593-47a3-8605-d14ba16296bb" xlink:to="loc_us-gaap_PatentedTechnologyMember_fda76f6d-32c6-435a-8a47-168597853bea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:to="loc_us-gaap_AssetAcquisitionAxis_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8" xlink:to="loc_us-gaap_AssetAcquisitionDomain_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_f4946d4b-ded2-496c-95ea-1af840f5877b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_e7f6aef4-cd83-4c20-a07b-14f4b71fdaa8" xlink:to="loc_us-gaap_AssetAcquisitionDomain_f4946d4b-ded2-496c-95ea-1af840f5877b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AssetsRelatedToSealingAndImpregnationOfMetalCastingsMember_4865e45e-bcb9-454c-9201-65ef9a0c5ffe" xlink:href="kwr-20241231.xsd#kwr_AssetsRelatedToSealingAndImpregnationOfMetalCastingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_f4946d4b-ded2-496c-95ea-1af840f5877b" xlink:to="loc_kwr_AssetsRelatedToSealingAndImpregnationOfMetalCastingsMember_4865e45e-bcb9-454c-9201-65ef9a0c5ffe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_3b52a32b-c240-471d-955c-e590a6ababc4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_2cb505cc-dc2c-4b4d-b3f7-b4ccc3d92d7e" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_3b52a32b-c240-471d-955c-e590a6ababc4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_3b52a32b-c240-471d-955c-e590a6ababc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_3b52a32b-c240-471d-955c-e590a6ababc4" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_3b52a32b-c240-471d-955c-e590a6ababc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_fb8cf35c-68d3-4065-bd6b-20daa0ed0e82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_3b52a32b-c240-471d-955c-e590a6ababc4" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_fb8cf35c-68d3-4065-bd6b-20daa0ed0e82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_a0d1ebc0-7cc7-401b-b803-c136bc415564" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_fb8cf35c-68d3-4065-bd6b-20daa0ed0e82" xlink:to="loc_us-gaap_SubsequentEventMember_a0d1ebc0-7cc7-401b-b803-c136bc415564" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_5a56efd6-3220-4689-bed9-4e70ccde6efb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_5a56efd6-3220-4689-bed9-4e70ccde6efb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_4f1981e1-5e7e-4f00-bc07-916f3cce49ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_4f1981e1-5e7e-4f00-bc07-916f3cce49ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_152c23ee-7df4-43c8-bdda-3c00224b1fe6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_152c23ee-7df4-43c8-bdda-3c00224b1fe6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_f6b35d3d-abd3-498f-b5a1-e7185a4bb923" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_f6b35d3d-abd3-498f-b5a1-e7185a4bb923" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EarnoutLiabilityAdjustment_2d24799b-949a-45dc-a6c2-fcdfbc773293" xlink:href="kwr-20241231.xsd#kwr_EarnoutLiabilityAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_kwr_EarnoutLiabilityAdjustment_2d24799b-949a-45dc-a6c2-fcdfbc773293" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_5b161516-6065-44c6-a524-3aea8d4929d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_5b161516-6065-44c6-a524-3aea8d4929d0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_3f733d56-17de-4c54-9c34-8575bfa2f6af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_Goodwill_3f733d56-17de-4c54-9c34-8575bfa2f6af" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_bd93de63-610d-4c60-96ca-b8bcdec14890" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_bd93de63-610d-4c60-96ca-b8bcdec14890" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_35b65066-f09a-4641-a4f6-c861c12b2805" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_35b65066-f09a-4641-a4f6-c861c12b2805" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_99af6086-38f2-4abb-8c75-a13020128ef2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_99af6086-38f2-4abb-8c75-a13020128ef2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_9810ddbb-b273-44b0-9438-6ed2bde250ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_421dace5-6d42-41e1-8689-6d9f2450fba3" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferred_9810ddbb-b273-44b0-9438-6ed2bde250ac" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessSegmentsInformationofCompanysReportableSegmentsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessSegmentsInformationofCompanysReportableSegmentsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessSegmentsInformationofCompanysReportableSegmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_6a46dc5f-e6a8-46ca-ad60-1cd948f772dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_6a46dc5f-e6a8-46ca-ad60-1cd948f772dc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_b1a42275-31b0-41b3-baf8-1894ce34d13a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_6a46dc5f-e6a8-46ca-ad60-1cd948f772dc" xlink:to="loc_srt_ConsolidationItemsAxis_b1a42275-31b0-41b3-baf8-1894ce34d13a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_b1a42275-31b0-41b3-baf8-1894ce34d13a_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_b1a42275-31b0-41b3-baf8-1894ce34d13a" xlink:to="loc_srt_ConsolidationItemsDomain_b1a42275-31b0-41b3-baf8-1894ce34d13a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_f583da86-e28d-4731-82ba-230d22694b72" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_b1a42275-31b0-41b3-baf8-1894ce34d13a" xlink:to="loc_srt_ConsolidationItemsDomain_f583da86-e28d-4731-82ba-230d22694b72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_a5a817cb-6599-4285-9c1a-472ec5c54b6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_f583da86-e28d-4731-82ba-230d22694b72" xlink:to="loc_us-gaap_OperatingSegmentsMember_a5a817cb-6599-4285-9c1a-472ec5c54b6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_4f5c82f6-7097-4283-9edc-d6da67d965c4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_6a46dc5f-e6a8-46ca-ad60-1cd948f772dc" xlink:to="loc_srt_StatementGeographicalAxis_4f5c82f6-7097-4283-9edc-d6da67d965c4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_4f5c82f6-7097-4283-9edc-d6da67d965c4_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_4f5c82f6-7097-4283-9edc-d6da67d965c4" xlink:to="loc_srt_SegmentGeographicalDomain_4f5c82f6-7097-4283-9edc-d6da67d965c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_15a5a942-c096-4101-b7bb-82c9b6dfbe5c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_4f5c82f6-7097-4283-9edc-d6da67d965c4" xlink:to="loc_srt_SegmentGeographicalDomain_15a5a942-c096-4101-b7bb-82c9b6dfbe5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_bccd9bcc-100a-4573-b3ab-156de859947a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_15a5a942-c096-4101-b7bb-82c9b6dfbe5c" xlink:to="loc_srt_AmericasMember_bccd9bcc-100a-4573-b3ab-156de859947a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_84c441dd-a396-459e-9b92-6d870af475d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_15a5a942-c096-4101-b7bb-82c9b6dfbe5c" xlink:to="loc_us-gaap_EMEAMember_84c441dd-a396-459e-9b92-6d870af475d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_d4642a7a-0139-43ce-a98b-1a7fbcaee3b8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_15a5a942-c096-4101-b7bb-82c9b6dfbe5c" xlink:to="loc_srt_AsiaPacificMember_d4642a7a-0139-43ce-a98b-1a7fbcaee3b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a14fd9db-5d67-4880-a9e3-4dd4a08129fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a14fd9db-5d67-4880-a9e3-4dd4a08129fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductionAndDistributionCosts_ee577ee3-eab9-411c-bdd7-df00cd0b05c5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductionAndDistributionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:to="loc_us-gaap_ProductionAndDistributionCosts_ee577ee3-eab9-411c-bdd7-df00cd0b05c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_38b9a440-1339-4cee-b8b7-d24b5fd14ca4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_38b9a440-1339-4cee-b8b7-d24b5fd14ca4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OperatingIncomeLossSegmentReporting_4f583148-4fb4-4edd-b3a0-9ff1fff408c1" xlink:href="kwr-20241231.xsd#kwr_OperatingIncomeLossSegmentReporting"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_822fd73e-f7f0-491a-a066-7e7cb0f7eb8f" xlink:to="loc_kwr_OperatingIncomeLossSegmentReporting_4f583148-4fb4-4edd-b3a0-9ff1fff408c1" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessSegmentsScheduleofSegmentAssetsandLongLivedAssetsExcludingGoodwillDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessSegmentsScheduleofSegmentAssetsandLongLivedAssetsExcludingGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessSegmentsScheduleofSegmentAssetsandLongLivedAssetsExcludingGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_18a0c400-6f4e-4e40-bbf6-2a5c0fe45a67" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_ac8bcb50-764f-4baa-95fd-8b6058ce6abb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_18a0c400-6f4e-4e40-bbf6-2a5c0fe45a67" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_ac8bcb50-764f-4baa-95fd-8b6058ce6abb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_ac8bcb50-764f-4baa-95fd-8b6058ce6abb" xlink:to="loc_srt_StatementGeographicalAxis_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9" xlink:to="loc_srt_SegmentGeographicalDomain_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_e56412d5-caa9-4a8c-8747-ef200de79658" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_e5774ca2-a1be-4926-a2f9-04a8df8c1fc9" xlink:to="loc_srt_SegmentGeographicalDomain_e56412d5-caa9-4a8c-8747-ef200de79658" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_ab482fcb-f550-4add-bff4-e0133832eb23" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e56412d5-caa9-4a8c-8747-ef200de79658" xlink:to="loc_srt_AmericasMember_ab482fcb-f550-4add-bff4-e0133832eb23" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_3521919c-225a-40f6-8df5-61de17175853" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e56412d5-caa9-4a8c-8747-ef200de79658" xlink:to="loc_us-gaap_EMEAMember_3521919c-225a-40f6-8df5-61de17175853" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_84435e79-7f91-40ce-8189-2876f7c6a64f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_e56412d5-caa9-4a8c-8747-ef200de79658" xlink:to="loc_srt_AsiaPacificMember_84435e79-7f91-40ce-8189-2876f7c6a64f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AssetsExcludingGoodwill_6d61ed51-f5c3-41fa-ab6e-fe887b6f2844" xlink:href="kwr-20241231.xsd#kwr_AssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_18a0c400-6f4e-4e40-bbf6-2a5c0fe45a67" xlink:to="loc_kwr_AssetsExcludingGoodwill_6d61ed51-f5c3-41fa-ab6e-fe887b6f2844" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_209f0980-bbdb-467f-b397-ad2cd29f7446" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_18a0c400-6f4e-4e40-bbf6-2a5c0fe45a67" xlink:to="loc_us-gaap_NoncurrentAssets_209f0980-bbdb-467f-b397-ad2cd29f7446" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessSegmentsScheduleofCapitalExpendituresandDepreciationforIdentifiableAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessSegmentsScheduleofCapitalExpendituresandDepreciationforIdentifiableAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessSegmentsScheduleofCapitalExpendituresandDepreciationforIdentifiableAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_29c6bb1b-aa75-4002-8e3a-b696704a5239" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1b466b39-04fd-4f13-9510-65a1ad8b7d3a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_29c6bb1b-aa75-4002-8e3a-b696704a5239" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1b466b39-04fd-4f13-9510-65a1ad8b7d3a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_d494f4df-5d1b-48e4-8c88-8054b1fda069" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1b466b39-04fd-4f13-9510-65a1ad8b7d3a" xlink:to="loc_srt_StatementGeographicalAxis_d494f4df-5d1b-48e4-8c88-8054b1fda069" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_d494f4df-5d1b-48e4-8c88-8054b1fda069_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_d494f4df-5d1b-48e4-8c88-8054b1fda069" xlink:to="loc_srt_SegmentGeographicalDomain_d494f4df-5d1b-48e4-8c88-8054b1fda069_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_79c2f68c-0f89-4d3d-bfcf-4f3876804c13" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_d494f4df-5d1b-48e4-8c88-8054b1fda069" xlink:to="loc_srt_SegmentGeographicalDomain_79c2f68c-0f89-4d3d-bfcf-4f3876804c13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_2261cfb7-a855-452e-8d8b-df2026c730aa" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_79c2f68c-0f89-4d3d-bfcf-4f3876804c13" xlink:to="loc_srt_AmericasMember_2261cfb7-a855-452e-8d8b-df2026c730aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_c910f0cb-cd39-4efc-81be-bf2493c93a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_79c2f68c-0f89-4d3d-bfcf-4f3876804c13" xlink:to="loc_us-gaap_EMEAMember_c910f0cb-cd39-4efc-81be-bf2493c93a4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_25df2feb-822c-415d-85c6-1c00f62f9946" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_79c2f68c-0f89-4d3d-bfcf-4f3876804c13" xlink:to="loc_srt_AsiaPacificMember_25df2feb-822c-415d-85c6-1c00f62f9946" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_34b6a647-d6a2-43f9-8be0-168840ca900c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_29c6bb1b-aa75-4002-8e3a-b696704a5239" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_34b6a647-d6a2-43f9-8be0-168840ca900c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDepreciationAndAmortization_012adc48-7303-4a00-b270-6ffea477d16d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_29c6bb1b-aa75-4002-8e3a-b696704a5239" xlink:to="loc_us-gaap_OtherDepreciationAndAmortization_012adc48-7303-4a00-b270-6ffea477d16d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessSegmentsScheduleofNetSalesandLongLivedAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessSegmentsScheduleofNetSalesandLongLivedAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessSegmentsScheduleofNetSalesandLongLivedAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_58fe5e5a-5c91-4722-954c-ac36a0221f60" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_e6dec836-1a07-4734-8da8-18eaaf192a98" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_58fe5e5a-5c91-4722-954c-ac36a0221f60" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_e6dec836-1a07-4734-8da8-18eaaf192a98" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_d39e3f5c-1c9f-4fb1-afec-52fede342ece" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_e6dec836-1a07-4734-8da8-18eaaf192a98" xlink:to="loc_srt_StatementGeographicalAxis_d39e3f5c-1c9f-4fb1-afec-52fede342ece" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_d39e3f5c-1c9f-4fb1-afec-52fede342ece_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_d39e3f5c-1c9f-4fb1-afec-52fede342ece" xlink:to="loc_srt_SegmentGeographicalDomain_d39e3f5c-1c9f-4fb1-afec-52fede342ece_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_d39e3f5c-1c9f-4fb1-afec-52fede342ece" xlink:to="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_2eed7a52-d644-4ed7-b496-c752d03d7455" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:to="loc_country_US_2eed7a52-d644-4ed7-b496-c752d03d7455" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_e8b72e4d-1eba-4224-ad15-ffc75fb5a919" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:to="loc_country_CN_e8b72e4d-1eba-4224-ad15-ffc75fb5a919" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OtherNonUSExcludingChinaMember_73abaf74-a465-451f-afdc-4708d98d3223" xlink:href="kwr-20241231.xsd#kwr_OtherNonUSExcludingChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:to="loc_kwr_OtherNonUSExcludingChinaMember_73abaf74-a465-451f-afdc-4708d98d3223" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_2056eed3-e3a5-4ded-8afd-ce624bff32ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_b689b60c-e757-49b7-870f-da59b4acd32a" xlink:to="loc_us-gaap_NonUsMember_2056eed3-e3a5-4ded-8afd-ce624bff32ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d57259fe-bb87-40c5-827d-06860677e636" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_58fe5e5a-5c91-4722-954c-ac36a0221f60" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d57259fe-bb87-40c5-827d-06860677e636" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_7ccfacf7-21c7-46c1-8346-597df6da7f98" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_58fe5e5a-5c91-4722-954c-ac36a0221f60" xlink:to="loc_us-gaap_NoncurrentAssets_7ccfacf7-21c7-46c1-8346-597df6da7f98" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/BusinessSegmentsInformationofIntersegmentRevenueDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#BusinessSegmentsInformationofIntersegmentRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/BusinessSegmentsInformationofIntersegmentRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_ff717d0d-2e57-489a-8080-15a248aead77" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_341e2d40-fb1a-4a57-8163-b27f07e7ddbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ff717d0d-2e57-489a-8080-15a248aead77" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_341e2d40-fb1a-4a57-8163-b27f07e7ddbe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_341e2d40-fb1a-4a57-8163-b27f07e7ddbe" xlink:to="loc_srt_ConsolidationItemsAxis_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353" xlink:to="loc_srt_ConsolidationItemsDomain_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_b37d7d6d-a11b-4a00-9b3a-2f07e5d5a0b6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_1b20e07c-6f15-4408-9e1b-e1b9c3fdc353" xlink:to="loc_srt_ConsolidationItemsDomain_b37d7d6d-a11b-4a00-9b3a-2f07e5d5a0b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_025612a8-2afb-41a9-94e3-cc041021b8eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_b37d7d6d-a11b-4a00-9b3a-2f07e5d5a0b6" xlink:to="loc_us-gaap_IntersegmentEliminationMember_025612a8-2afb-41a9-94e3-cc041021b8eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_341e2d40-fb1a-4a57-8163-b27f07e7ddbe" xlink:to="loc_srt_StatementGeographicalAxis_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4" xlink:to="loc_srt_SegmentGeographicalDomain_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2c9ab7f1-5d2d-416f-9568-ed2d3350b9ca" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_c7903e9f-9d8c-4ed9-b37b-8d3f83e6c3a4" xlink:to="loc_srt_SegmentGeographicalDomain_2c9ab7f1-5d2d-416f-9568-ed2d3350b9ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_afcfa136-5a1d-4d04-8332-e0cc28f87fd6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2c9ab7f1-5d2d-416f-9568-ed2d3350b9ca" xlink:to="loc_srt_AmericasMember_afcfa136-5a1d-4d04-8332-e0cc28f87fd6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_054a28fa-8dc1-41fa-892e-5b0c81b0946a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2c9ab7f1-5d2d-416f-9568-ed2d3350b9ca" xlink:to="loc_us-gaap_EMEAMember_054a28fa-8dc1-41fa-892e-5b0c81b0946a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_efff2f2b-a0f3-4e6c-ab1d-3061ff3f89a0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2c9ab7f1-5d2d-416f-9568-ed2d3350b9ca" xlink:to="loc_srt_AsiaPacificMember_efff2f2b-a0f3-4e6c-ab1d-3061ff3f89a0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_be79ff7a-bc1f-44f8-a5bc-410e03a82e02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_ff717d0d-2e57-489a-8080-15a248aead77" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_be79ff7a-bc1f-44f8-a5bc-410e03a82e02" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#NetSalesandRevenueRecognitionNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_340c0590-0d2a-4153-97fd-48f60fe9238f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:to="loc_us-gaap_ConcentrationRiskTable_340c0590-0d2a-4153-97fd-48f60fe9238f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_13d55927-d1f2-4dae-8950-902a3e4cb32c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_340c0590-0d2a-4153-97fd-48f60fe9238f" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_13d55927-d1f2-4dae-8950-902a3e4cb32c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_13d55927-d1f2-4dae-8950-902a3e4cb32c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_13d55927-d1f2-4dae-8950-902a3e4cb32c" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_13d55927-d1f2-4dae-8950-902a3e4cb32c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_13f636f7-9d21-4bca-ac38-a5ccab899596" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_13d55927-d1f2-4dae-8950-902a3e4cb32c" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_13f636f7-9d21-4bca-ac38-a5ccab899596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_fc3b88c1-2a60-4e28-a7c9-fece0b45f4f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_13f636f7-9d21-4bca-ac38-a5ccab899596" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_fc3b88c1-2a60-4e28-a7c9-fece0b45f4f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a01642-d65d-4d29-b00e-167b8b0130fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_340c0590-0d2a-4153-97fd-48f60fe9238f" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a01642-d65d-4d29-b00e-167b8b0130fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d4a01642-d65d-4d29-b00e-167b8b0130fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a01642-d65d-4d29-b00e-167b8b0130fc" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d4a01642-d65d-4d29-b00e-167b8b0130fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3224a7ff-29fd-4948-b052-89943853f4c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a01642-d65d-4d29-b00e-167b8b0130fc" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3224a7ff-29fd-4948-b052-89943853f4c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_8b792eaf-e216-4db1-a337-12ff7fde66f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3224a7ff-29fd-4948-b052-89943853f4c0" xlink:to="loc_us-gaap_SalesRevenueNetMember_8b792eaf-e216-4db1-a337-12ff7fde66f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_88ae0132-14e1-4ed0-b2e4-c5417ad53f37" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_340c0590-0d2a-4153-97fd-48f60fe9238f" xlink:to="loc_srt_MajorCustomersAxis_88ae0132-14e1-4ed0-b2e4-c5417ad53f37" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_88ae0132-14e1-4ed0-b2e4-c5417ad53f37_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_88ae0132-14e1-4ed0-b2e4-c5417ad53f37" xlink:to="loc_srt_NameOfMajorCustomerDomain_88ae0132-14e1-4ed0-b2e4-c5417ad53f37_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_e6293e78-b29e-476c-aef0-2d5255715f68" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_88ae0132-14e1-4ed0-b2e4-c5417ad53f37" xlink:to="loc_srt_NameOfMajorCustomerDomain_e6293e78-b29e-476c-aef0-2d5255715f68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_CustomerConcentrationRiskTopFiveMember_edeee45c-cb89-45eb-b22e-5dcfb3f219d8" xlink:href="kwr-20241231.xsd#kwr_CustomerConcentrationRiskTopFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_e6293e78-b29e-476c-aef0-2d5255715f68" xlink:to="loc_kwr_CustomerConcentrationRiskTopFiveMember_edeee45c-cb89-45eb-b22e-5dcfb3f219d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_LargestCustomerMember_ac0fd52e-6b14-4849-aaf2-3e620b258464" xlink:href="kwr-20241231.xsd#kwr_LargestCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_e6293e78-b29e-476c-aef0-2d5255715f68" xlink:to="loc_kwr_LargestCustomerMember_ac0fd52e-6b14-4849-aaf2-3e620b258464" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_Netreportingamount_20234f5a-d7d9-46a9-8ae6-be705b963a77" xlink:href="kwr-20241231.xsd#kwr_Netreportingamount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:to="loc_kwr_Netreportingamount_20234f5a-d7d9-46a9-8ae6-be705b963a77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_894cc101-cdcb-46f3-a639-f0af7bff9034" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_894cc101-cdcb-46f3-a639-f0af7bff9034" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredRevenue_45412496-39eb-46ad-ae47-39a457147310" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:to="loc_us-gaap_DeferredRevenue_45412496-39eb-46ad-ae47-39a457147310" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ProductLineAsPercentageOfConsolidatedNetSales_29c11f5b-de8b-4706-9860-a5de45a26c06" xlink:href="kwr-20241231.xsd#kwr_ProductLineAsPercentageOfConsolidatedNetSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_36e1ec63-99cc-4ece-9032-50f671cc4f0e" xlink:to="loc_kwr_ProductLineAsPercentageOfConsolidatedNetSales_29c11f5b-de8b-4706-9860-a5de45a26c06" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionMajorProductLinesDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#NetSalesandRevenueRecognitionMajorProductLinesDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionMajorProductLinesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_f8992387-df60-4710-aeef-33a4c2fb810b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfProductInformationTable_af0181af-0f0f-4965-abcf-013bf9020b3b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfProductInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_f8992387-df60-4710-aeef-33a4c2fb810b" xlink:to="loc_us-gaap_ScheduleOfProductInformationTable_af0181af-0f0f-4965-abcf-013bf9020b3b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_3cb0be10-c9a9-4882-a679-41ad92eb5d12" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_af0181af-0f0f-4965-abcf-013bf9020b3b" xlink:to="loc_srt_ProductOrServiceAxis_3cb0be10-c9a9-4882-a679-41ad92eb5d12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_3cb0be10-c9a9-4882-a679-41ad92eb5d12_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_3cb0be10-c9a9-4882-a679-41ad92eb5d12" xlink:to="loc_srt_ProductsAndServicesDomain_3cb0be10-c9a9-4882-a679-41ad92eb5d12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_4ee2d67e-a12e-4359-9da3-e8c735d453a1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_3cb0be10-c9a9-4882-a679-41ad92eb5d12" xlink:to="loc_srt_ProductsAndServicesDomain_4ee2d67e-a12e-4359-9da3-e8c735d453a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MetalRemovalFluidsLineMember_75bd4800-b312-4726-bb76-2cea7d2c0333" xlink:href="kwr-20241231.xsd#kwr_MetalRemovalFluidsLineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4ee2d67e-a12e-4359-9da3-e8c735d453a1" xlink:to="loc_kwr_MetalRemovalFluidsLineMember_75bd4800-b312-4726-bb76-2cea7d2c0333" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_RollingLubricantsProductLineMember_ede824cc-7440-4035-876e-c8fb14841515" xlink:href="kwr-20241231.xsd#kwr_RollingLubricantsProductLineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4ee2d67e-a12e-4359-9da3-e8c735d453a1" xlink:to="loc_kwr_RollingLubricantsProductLineMember_ede824cc-7440-4035-876e-c8fb14841515" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_HydraulicFluidsProductLineMember_e1c1ce54-41d6-430b-8548-e0d9bdd123ab" xlink:href="kwr-20241231.xsd#kwr_HydraulicFluidsProductLineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4ee2d67e-a12e-4359-9da3-e8c735d453a1" xlink:to="loc_kwr_HydraulicFluidsProductLineMember_e1c1ce54-41d6-430b-8548-e0d9bdd123ab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_44e8e1a7-c5ed-46c0-b125-a27237d95855" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_af0181af-0f0f-4965-abcf-013bf9020b3b" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_44e8e1a7-c5ed-46c0-b125-a27237d95855" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_44e8e1a7-c5ed-46c0-b125-a27237d95855_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_44e8e1a7-c5ed-46c0-b125-a27237d95855" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_44e8e1a7-c5ed-46c0-b125-a27237d95855_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_74e8208d-4cdb-4fa5-aa35-52e522665896" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_44e8e1a7-c5ed-46c0-b125-a27237d95855" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_74e8208d-4cdb-4fa5-aa35-52e522665896" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember_b4cd5835-fa56-4add-903d-3dc4d2183153" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SalesRevenueNetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_74e8208d-4cdb-4fa5-aa35-52e522665896" xlink:to="loc_us-gaap_SalesRevenueNetMember_b4cd5835-fa56-4add-903d-3dc4d2183153" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_af0181af-0f0f-4965-abcf-013bf9020b3b" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_a9908273-b2aa-4503-9bc6-6fc91b2ea441" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_8735ffe9-0c2e-4d6e-bb48-a6cf805f7b7d" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_a9908273-b2aa-4503-9bc6-6fc91b2ea441" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_17654814-b467-4ad5-9e03-bb498cc4f5e3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_a9908273-b2aa-4503-9bc6-6fc91b2ea441" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_17654814-b467-4ad5-9e03-bb498cc4f5e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_2eb41958-3a15-439e-be3d-153cee7b57aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_f8992387-df60-4710-aeef-33a4c2fb810b" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_2eb41958-3a15-439e-be3d-153cee7b57aa" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionDisaggregationoftheCompanysnetsalesDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#NetSalesandRevenueRecognitionDisaggregationoftheCompanysnetsalesDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/NetSalesandRevenueRecognitionDisaggregationoftheCompanysnetsalesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductInformationLineItems_dac3216d-da3f-4a14-970f-3c2be0976db7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfProductInformationTable_a781485d-80c9-478c-b5a2-68558b6ced2a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfProductInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductInformationLineItems_dac3216d-da3f-4a14-970f-3c2be0976db7" xlink:to="loc_us-gaap_ScheduleOfProductInformationTable_a781485d-80c9-478c-b5a2-68558b6ced2a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_df70d137-e87c-4292-9c50-a8cf78e6701b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_a781485d-80c9-478c-b5a2-68558b6ced2a" xlink:to="loc_srt_ConsolidationItemsAxis_df70d137-e87c-4292-9c50-a8cf78e6701b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_df70d137-e87c-4292-9c50-a8cf78e6701b_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_df70d137-e87c-4292-9c50-a8cf78e6701b" xlink:to="loc_srt_ConsolidationItemsDomain_df70d137-e87c-4292-9c50-a8cf78e6701b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_c5b3de9d-75df-451a-abd7-5ffec26675b5" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_df70d137-e87c-4292-9c50-a8cf78e6701b" xlink:to="loc_srt_ConsolidationItemsDomain_c5b3de9d-75df-451a-abd7-5ffec26675b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_c0079f33-e392-45e6-93dc-e0d1f7097129" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_c5b3de9d-75df-451a-abd7-5ffec26675b5" xlink:to="loc_us-gaap_OperatingSegmentsMember_c0079f33-e392-45e6-93dc-e0d1f7097129" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_ee941b48-be1f-4a28-8370-a73e5c1841c5" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_a781485d-80c9-478c-b5a2-68558b6ced2a" xlink:to="loc_srt_StatementGeographicalAxis_ee941b48-be1f-4a28-8370-a73e5c1841c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_ee941b48-be1f-4a28-8370-a73e5c1841c5_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_ee941b48-be1f-4a28-8370-a73e5c1841c5" xlink:to="loc_srt_SegmentGeographicalDomain_ee941b48-be1f-4a28-8370-a73e5c1841c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_d3da86fd-0369-4ba7-8c90-ec3abe774201" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_ee941b48-be1f-4a28-8370-a73e5c1841c5" xlink:to="loc_srt_SegmentGeographicalDomain_d3da86fd-0369-4ba7-8c90-ec3abe774201" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_7b3472e3-761c-4ef4-995c-a1c0462d1309" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d3da86fd-0369-4ba7-8c90-ec3abe774201" xlink:to="loc_srt_AmericasMember_7b3472e3-761c-4ef4-995c-a1c0462d1309" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_e55bc5e7-f1f5-4ed9-ae1d-da2eea41d602" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d3da86fd-0369-4ba7-8c90-ec3abe774201" xlink:to="loc_us-gaap_EMEAMember_e55bc5e7-f1f5-4ed9-ae1d-da2eea41d602" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_f28187ba-eaf0-4a0f-93cb-cb36d194a85a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_d3da86fd-0369-4ba7-8c90-ec3abe774201" xlink:to="loc_srt_AsiaPacificMember_f28187ba-eaf0-4a0f-93cb-cb36d194a85a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_511aa255-71ae-4a6a-b045-b06ac58ba2ac" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_a781485d-80c9-478c-b5a2-68558b6ced2a" xlink:to="loc_srt_ProductOrServiceAxis_511aa255-71ae-4a6a-b045-b06ac58ba2ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_511aa255-71ae-4a6a-b045-b06ac58ba2ac_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_511aa255-71ae-4a6a-b045-b06ac58ba2ac" xlink:to="loc_srt_ProductsAndServicesDomain_511aa255-71ae-4a6a-b045-b06ac58ba2ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_d4a29834-e835-43c3-bd9b-b9c0426576e8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_511aa255-71ae-4a6a-b045-b06ac58ba2ac" xlink:to="loc_srt_ProductsAndServicesDomain_d4a29834-e835-43c3-bd9b-b9c0426576e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_88f555a6-d60a-43cc-9f78-c9d23afd6470" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d4a29834-e835-43c3-bd9b-b9c0426576e8" xlink:to="loc_us-gaap_ProductMember_88f555a6-d60a-43cc-9f78-c9d23afd6470" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MetalsMember_4faba5f4-dfbe-4435-a101-2de17d63e890" xlink:href="kwr-20241231.xsd#kwr_MetalsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_88f555a6-d60a-43cc-9f78-c9d23afd6470" xlink:to="loc_kwr_MetalsMember_4faba5f4-dfbe-4435-a101-2de17d63e890" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MetalworkingMember_67ec103c-6ff1-4df8-90de-852f7e3ce623" xlink:href="kwr-20241231.xsd#kwr_MetalworkingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductMember_88f555a6-d60a-43cc-9f78-c9d23afd6470" xlink:to="loc_kwr_MetalworkingMember_67ec103c-6ff1-4df8-90de-852f7e3ce623" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a6d688c7-d26e-406b-bb19-b08ce95be6e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_dac3216d-da3f-4a14-970f-3c2be0976db7" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_a6d688c7-d26e-406b-bb19-b08ce95be6e1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/LeasesNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#LeasesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/LeasesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_8da787a4-7136-47a7-993f-a3fda753c083" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_8da787a4-7136-47a7-993f-a3fda753c083" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_4db67c77-c498-4c01-af9e-02e9f904eb17" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_8da787a4-7136-47a7-993f-a3fda753c083" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_4db67c77-c498-4c01-af9e-02e9f904eb17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4db67c77-c498-4c01-af9e-02e9f904eb17_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_4db67c77-c498-4c01-af9e-02e9f904eb17" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_4db67c77-c498-4c01-af9e-02e9f904eb17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8b75cd57-409e-49c2-8cc7-8c01299b7a65" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_4db67c77-c498-4c01-af9e-02e9f904eb17" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8b75cd57-409e-49c2-8cc7-8c01299b7a65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_FacilitiesVehiclesAndMachineryAndEquipmentMember_ed233ff1-b005-4f60-abe5-c280353ffdfb" xlink:href="kwr-20241231.xsd#kwr_FacilitiesVehiclesAndMachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8b75cd57-409e-49c2-8cc7-8c01299b7a65" xlink:to="loc_kwr_FacilitiesVehiclesAndMachineryAndEquipmentMember_ed233ff1-b005-4f60-abe5-c280353ffdfb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_86ccbad0-eb78-4576-967c-8da8148dea2d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_8b75cd57-409e-49c2-8cc7-8c01299b7a65" xlink:to="loc_us-gaap_LandMember_86ccbad0-eb78-4576-967c-8da8148dea2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b424aa45-6268-4185-9a2e-bb89cda29276" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_8da787a4-7136-47a7-993f-a3fda753c083" xlink:to="loc_srt_RangeAxis_b424aa45-6268-4185-9a2e-bb89cda29276" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b424aa45-6268-4185-9a2e-bb89cda29276_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b424aa45-6268-4185-9a2e-bb89cda29276" xlink:to="loc_srt_RangeMember_b424aa45-6268-4185-9a2e-bb89cda29276_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8d620ee1-9acf-4cf9-ab54-8e1d0319b4d8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b424aa45-6268-4185-9a2e-bb89cda29276" xlink:to="loc_srt_RangeMember_8d620ee1-9acf-4cf9-ab54-8e1d0319b4d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_0608d262-b7a8-4ee9-b9ac-b48cb5507269" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_8d620ee1-9acf-4cf9-ab54-8e1d0319b4d8" xlink:to="loc_srt_MaximumMember_0608d262-b7a8-4ee9-b9ac-b48cb5507269" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_9a9cde7b-22f4-4260-b179-c8e6a75cd3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseRemainingLeaseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:to="loc_us-gaap_LesseeOperatingLeaseRemainingLeaseTerm_9a9cde7b-22f4-4260-b179-c8e6a75cd3e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost_07e94fba-03fe-4b4b-bde3-3fbeaf5e21bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableLeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:to="loc_us-gaap_VariableLeaseCost_07e94fba-03fe-4b4b-bde3-3fbeaf5e21bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_506bab97-1c42-464d-9841-7afff9c9bbb9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubleaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:to="loc_us-gaap_SubleaseIncome_506bab97-1c42-464d-9841-7afff9c9bbb9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_69e4daba-a6c6-4877-b964-e01872a90eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_d46927fb-7df9-428b-99c7-babc49477a10" xlink:to="loc_us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_69e4daba-a6c6-4877-b964-e01872a90eb7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/RestructuringandRelatedActivitiesDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#RestructuringandRelatedActivitiesDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/RestructuringandRelatedActivitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_e53aec26-68c2-43f0-85d7-634f29fb6bfd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_290800a7-9d0e-4cab-91d6-7009b98517e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_e53aec26-68c2-43f0-85d7-634f29fb6bfd" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_290800a7-9d0e-4cab-91d6-7009b98517e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_84ee70d0-3aed-4792-89bb-3bda109fdf1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_290800a7-9d0e-4cab-91d6-7009b98517e7" xlink:to="loc_us-gaap_RestructuringPlanAxis_84ee70d0-3aed-4792-89bb-3bda109fdf1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_84ee70d0-3aed-4792-89bb-3bda109fdf1a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_84ee70d0-3aed-4792-89bb-3bda109fdf1a" xlink:to="loc_us-gaap_RestructuringPlanDomain_84ee70d0-3aed-4792-89bb-3bda109fdf1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_b5c15caa-3967-4765-9f4c-bd0768033612" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_84ee70d0-3aed-4792-89bb-3bda109fdf1a" xlink:to="loc_us-gaap_RestructuringPlanDomain_b5c15caa-3967-4765-9f4c-bd0768033612" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringChargesMember_36127955-5a22-4827-8688-c7cf77fefb2b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringChargesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_b5c15caa-3967-4765-9f4c-bd0768033612" xlink:to="loc_us-gaap_RestructuringChargesMember_36127955-5a22-4827-8688-c7cf77fefb2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_e53aec26-68c2-43f0-85d7-634f29fb6bfd" xlink:to="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_b3929611-cb83-4c3a-a33d-a8df70156b57" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserve"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:to="loc_us-gaap_RestructuringReserve_b3929611-cb83-4c3a-a33d-a8df70156b57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeveranceCosts1_ad7507c3-1061-479c-874c-f53ec563651e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeveranceCosts1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:to="loc_us-gaap_SeveranceCosts1_ad7507c3-1061-479c-874c-f53ec563651e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_f4f8c595-ec5f-4ae9-aefc-f72230f43056" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:to="loc_us-gaap_RestructuringCharges_f4f8c595-ec5f-4ae9-aefc-f72230f43056" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_042e0587-04fc-4087-93c0-c251bdc90973" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsForRestructuring"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:to="loc_us-gaap_PaymentsForRestructuring_042e0587-04fc-4087-93c0-c251bdc90973" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveTranslationAdjustment_f7275198-1af9-4275-ba8f-79ee3e101cfd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveTranslationAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_a2c1edff-c98e-4266-ad75-bc17b8d473c0" xlink:to="loc_us-gaap_RestructuringReserveTranslationAdjustment_f7275198-1af9-4275-ba8f-79ee3e101cfd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_54ca2959-fc8f-4752-94b6-ff831e36a726" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserve"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/EquityExpenseTableDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#EquityExpenseTableDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/EquityExpenseTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_586c39f9-3f96-4f89-a4fe-b050ba7d6c7d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_f1c25a96-c1ac-40ed-8c52-82fa5ac92ece" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_586c39f9-3f96-4f89-a4fe-b050ba7d6c7d" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_f1c25a96-c1ac-40ed-8c52-82fa5ac92ece" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9f88e1ef-124e-458e-96c8-0b8b3f3d3326" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_f1c25a96-c1ac-40ed-8c52-82fa5ac92ece" xlink:to="loc_us-gaap_AwardTypeAxis_9f88e1ef-124e-458e-96c8-0b8b3f3d3326" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9f88e1ef-124e-458e-96c8-0b8b3f3d3326_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9f88e1ef-124e-458e-96c8-0b8b3f3d3326" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9f88e1ef-124e-458e-96c8-0b8b3f3d3326_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9f88e1ef-124e-458e-96c8-0b8b3f3d3326" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_StockOptionsCompensationExpenseMember_a3c9fc16-7134-4caa-8dee-c80d2f5ac541" xlink:href="kwr-20241231.xsd#kwr_StockOptionsCompensationExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:to="loc_kwr_StockOptionsCompensationExpenseMember_a3c9fc16-7134-4caa-8dee-c80d2f5ac541" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_NonvestedStockAwardsCompensationExpenseMember_16c53209-68c7-45da-954b-a70ac065819b" xlink:href="kwr-20241231.xsd#kwr_NonvestedStockAwardsCompensationExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:to="loc_kwr_NonvestedStockAwardsCompensationExpenseMember_16c53209-68c7-45da-954b-a70ac065819b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorsStockOwnershipPlanCompensationExpenseMember_46814127-1079-4973-a63e-f2868e8f2c00" xlink:href="kwr-20241231.xsd#kwr_DirectorsStockOwnershipPlanCompensationExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:to="loc_kwr_DirectorsStockOwnershipPlanCompensationExpenseMember_46814127-1079-4973-a63e-f2868e8f2c00" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PerformanceIncentiveStockUnitsMember_79e24760-271f-47fb-8906-5e77e613ef05" xlink:href="kwr-20241231.xsd#kwr_PerformanceIncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c549bd3-255f-472c-b3d5-4265969549e9" xlink:to="loc_kwr_PerformanceIncentiveStockUnitsMember_79e24760-271f-47fb-8906-5e77e613ef05" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_2fc58da1-68ac-4686-88ee-8c1ce0d153e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_586c39f9-3f96-4f89-a4fe-b050ba7d6c7d" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_2fc58da1-68ac-4686-88ee-8c1ce0d153e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_dae4d45e-48cd-4fe0-a534-1bace6a4e70a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_586c39f9-3f96-4f89-a4fe-b050ba7d6c7d" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_dae4d45e-48cd-4fe0-a534-1bace6a4e70a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_90397d90-8301-413a-86a2-e330eb1d81a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_586c39f9-3f96-4f89-a4fe-b050ba7d6c7d" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_90397d90-8301-413a-86a2-e330eb1d81a5" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/EquityNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#EquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/EquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_1431d7d7-18f5-4666-a408-989043a075b2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:to="loc_srt_RangeAxis_1431d7d7-18f5-4666-a408-989043a075b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_1431d7d7-18f5-4666-a408-989043a075b2_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_1431d7d7-18f5-4666-a408-989043a075b2" xlink:to="loc_srt_RangeMember_1431d7d7-18f5-4666-a408-989043a075b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9a55b053-03d3-4982-9f87-c0787e45e940" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_1431d7d7-18f5-4666-a408-989043a075b2" xlink:to="loc_srt_RangeMember_9a55b053-03d3-4982-9f87-c0787e45e940" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_79659cf8-5503-466d-9cae-cb96b83f7b1d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_9a55b053-03d3-4982-9f87-c0787e45e940" xlink:to="loc_srt_MinimumMember_79659cf8-5503-466d-9cae-cb96b83f7b1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_b7dcc2a7-cb54-4f99-ab71-7820c1702fb2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_9a55b053-03d3-4982-9f87-c0787e45e940" xlink:to="loc_srt_MaximumMember_b7dcc2a7-cb54-4f99-ab71-7820c1702fb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_35504792-fc3a-4b14-956a-27c902c5ef9c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:to="loc_us-gaap_AwardTypeAxis_35504792-fc3a-4b14-956a-27c902c5ef9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_35504792-fc3a-4b14-956a-27c902c5ef9c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_35504792-fc3a-4b14-956a-27c902c5ef9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_35504792-fc3a-4b14-956a-27c902c5ef9c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_35504792-fc3a-4b14-956a-27c902c5ef9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_26a569c1-dc55-46dd-ad39-041e91fb330d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:to="loc_us-gaap_EmployeeStockOptionMember_26a569c1-dc55-46dd-ad39-041e91fb330d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_4c286604-3aa2-4e15-888f-e16d7bb97fbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:to="loc_us-gaap_RestrictedStockMember_4c286604-3aa2-4e15-888f-e16d7bb97fbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_f2fbaad5-dc91-429b-b425-48934914f4e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_f2fbaad5-dc91-429b-b425-48934914f4e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_a7337239-e7a0-44b6-9912-3e5ebc43cd28" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:to="loc_us-gaap_StockCompensationPlanMember_a7337239-e7a0-44b6-9912-3e5ebc43cd28" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PerformanceIncentiveStockUnitsMember_30d1e0d4-5266-4e92-8d0a-02ba2c65a837" xlink:href="kwr-20241231.xsd#kwr_PerformanceIncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_90dd5888-ec10-4bd6-96cb-454b7c58093b" xlink:to="loc_kwr_PerformanceIncentiveStockUnitsMember_30d1e0d4-5266-4e92-8d0a-02ba2c65a837" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_4696f37e-be47-4331-ba70-082e88d40420" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:to="loc_srt_ShareRepurchaseProgramAxis_4696f37e-be47-4331-ba70-082e88d40420" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_4696f37e-be47-4331-ba70-082e88d40420_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_4696f37e-be47-4331-ba70-082e88d40420" xlink:to="loc_srt_ShareRepurchaseProgramDomain_4696f37e-be47-4331-ba70-082e88d40420_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_970d6d2c-c934-4835-bca8-28e2a3d97a4d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_4696f37e-be47-4331-ba70-082e88d40420" xlink:to="loc_srt_ShareRepurchaseProgramDomain_970d6d2c-c934-4835-bca8-28e2a3d97a4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ShareRepurchaseProgramMember_e7ec22fd-ffaa-4019-8eeb-a0b0d9fea702" xlink:href="kwr-20241231.xsd#kwr_ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_970d6d2c-c934-4835-bca8-28e2a3d97a4d" xlink:to="loc_kwr_ShareRepurchaseProgramMember_e7ec22fd-ffaa-4019-8eeb-a0b0d9fea702" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_A2024ShareRepurchaseProgramMember_df1180cc-3298-4e5f-8d51-fb85f8f5e13e" xlink:href="kwr-20241231.xsd#kwr_A2024ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_970d6d2c-c934-4835-bca8-28e2a3d97a4d" xlink:to="loc_kwr_A2024ShareRepurchaseProgramMember_df1180cc-3298-4e5f-8d51-fb85f8f5e13e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_dff7ddc4-8239-47af-b4c3-42681d4ae1bf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8beca80c-3a58-4559-bbf6-7b2ce0073780" xlink:to="loc_us-gaap_PlanNameAxis_dff7ddc4-8239-47af-b4c3-42681d4ae1bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_dff7ddc4-8239-47af-b4c3-42681d4ae1bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_dff7ddc4-8239-47af-b4c3-42681d4ae1bf" xlink:to="loc_us-gaap_PlanNameDomain_dff7ddc4-8239-47af-b4c3-42681d4ae1bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_214f8532-fb95-4a7a-8fa5-ab0b6beed3d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_dff7ddc4-8239-47af-b4c3-42681d4ae1bf" xlink:to="loc_us-gaap_PlanNameDomain_214f8532-fb95-4a7a-8fa5-ab0b6beed3d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityCompensationPlanMember_7074758a-bd65-483e-aa59-b87e0b59dd75" xlink:href="kwr-20241231.xsd#kwr_EquityCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_214f8532-fb95-4a7a-8fa5-ab0b6beed3d2" xlink:to="loc_kwr_EquityCompensationPlanMember_7074758a-bd65-483e-aa59-b87e0b59dd75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_c08edc05-8d23-4ce7-91d4-d896ed1b18b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_c08edc05-8d23-4ce7-91d4-d896ed1b18b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_eedfe9b2-ce4e-41b8-b678-4a4d1c9fd958" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_eedfe9b2-ce4e-41b8-b678-4a4d1c9fd958" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_bb5d9019-f1d3-48db-aedd-094e620785d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_bb5d9019-f1d3-48db-aedd-094e620785d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_184ac524-9aa6-4987-a0f2-a17abf072b02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_184ac524-9aa6-4987-a0f2-a17abf072b02" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_ec0123db-8c00-4dd8-8b01-7928be11525b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_ec0123db-8c00-4dd8-8b01-7928be11525b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_343bb5cd-9536-48e6-8ad0-8d581dc8699a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_343bb5cd-9536-48e6-8ad0-8d581dc8699a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_f47ac767-878b-49fe-8475-286242fc7f7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_f47ac767-878b-49fe-8475-286242fc7f7b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_VestingSharesTargetLowerPercent_36e02b99-2517-4677-9222-955f494d2e6a" xlink:href="kwr-20241231.xsd#kwr_VestingSharesTargetLowerPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_VestingSharesTargetLowerPercent_36e02b99-2517-4677-9222-955f494d2e6a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_VestingSharesTargetUpperPercent_224602c3-0264-4cf8-8afc-a3efa68af101" xlink:href="kwr-20241231.xsd#kwr_VestingSharesTargetUpperPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_VestingSharesTargetUpperPercent_224602c3-0264-4cf8-8afc-a3efa68af101" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_887d0a6e-2fd7-4d70-9b7e-788f858cff21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_887d0a6e-2fd7-4d70-9b7e-788f858cff21" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_9e5af4e1-2143-4217-bf96-c640c94a463a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_9e5af4e1-2143-4217-bf96-c640c94a463a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_b9a6aa99-1e03-45ef-997a-25d5be7df8c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_b9a6aa99-1e03-45ef-997a-25d5be7df8c6" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorStockOwnershipPercentageThreshold_541b77f7-d8a6-4143-a528-2c23017274ea" xlink:href="kwr-20241231.xsd#kwr_DirectorStockOwnershipPercentageThreshold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_DirectorStockOwnershipPercentageThreshold_541b77f7-d8a6-4143-a528-2c23017274ea" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorStockOwnershipPlanPercentageStock_daefdf7c-ed37-4d53-b154-d359db0f12c0" xlink:href="kwr-20241231.xsd#kwr_DirectorStockOwnershipPlanPercentageStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_DirectorStockOwnershipPlanPercentageStock_daefdf7c-ed37-4d53-b154-d359db0f12c0" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorStockOwnershipPlanPercentageCash_476637b7-774a-49e2-b9b0-95948be430b2" xlink:href="kwr-20241231.xsd#kwr_DirectorStockOwnershipPlanPercentageCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_DirectorStockOwnershipPlanPercentageCash_476637b7-774a-49e2-b9b0-95948be430b2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorStockOwnershipPlanPercentageTotal_1afbf668-5e81-47bb-9590-a4b604ba41a0" xlink:href="kwr-20241231.xsd#kwr_DirectorStockOwnershipPlanPercentageTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_DirectorStockOwnershipPlanPercentageTotal_1afbf668-5e81-47bb-9590-a4b604ba41a0" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DirectorRetainerAnnualFee_72fd3d2d-a97c-4c58-9031-876313afab43" xlink:href="kwr-20241231.xsd#kwr_DirectorRetainerAnnualFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_DirectorRetainerAnnualFee_72fd3d2d-a97c-4c58-9031-876313afab43" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_760c5eec-3cd2-421d-bca2-4cc9c97bae1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_760c5eec-3cd2-421d-bca2-4cc9c97bae1c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_41132658-916e-4447-82b9-0c9f95189f83" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_41132658-916e-4447-82b9-0c9f95189f83" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_e9922154-ab09-44e9-9dbd-017501480e25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_e9922154-ab09-44e9-9dbd-017501480e25" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_0c6810d2-0a1d-4e7f-89c2-900f6f845dbf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_CommonStockSharesIssued_0c6810d2-0a1d-4e7f-89c2-900f6f845dbf" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_101ed580-5aa5-4212-a56d-9853e9623530" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_101ed580-5aa5-4212-a56d-9853e9623530" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_f3117b58-db3d-4a24-8133-94525c892d48" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_f3117b58-db3d-4a24-8133-94525c892d48" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_663fdadd-bbf3-4219-af0a-9802b686b5b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_663fdadd-bbf3-4219-af0a-9802b686b5b0" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_6054f0ad-f875-437e-b20a-e907226769f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_PreferredStockSharesIssued_6054f0ad-f875-437e-b20a-e907226769f7" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_a9b556d2-f366-42ec-994b-67c22956d4f8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_a9b556d2-f366-42ec-994b-67c22956d4f8" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_f21aecc3-a2b1-44bd-a526-6a38f9014895" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_f21aecc3-a2b1-44bd-a526-6a38f9014895" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSurrenderedInPeriod_e32fe3ae-41b9-45da-a3b7-e00621264a4e" xlink:href="kwr-20241231.xsd#kwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSurrenderedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_kwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsSurrenderedInPeriod_e32fe3ae-41b9-45da-a3b7-e00621264a4e" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_da6b98e5-68ff-4e1b-9490-afe01fc2e3d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_b9429183-a4fd-40fd-8d0a-fb4171fd07fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_da6b98e5-68ff-4e1b-9490-afe01fc2e3d2" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/EquityValuationAssumptionsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#EquityValuationAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/EquityValuationAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_92cdf2ae-221e-4039-85b3-c492ae8ab267" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4f6fdc9c-9948-4e07-8fb1-7c2c2e4c93dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_92cdf2ae-221e-4039-85b3-c492ae8ab267" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4f6fdc9c-9948-4e07-8fb1-7c2c2e4c93dc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4f6fdc9c-9948-4e07-8fb1-7c2c2e4c93dc" xlink:to="loc_us-gaap_AwardTypeAxis_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_dcc87cc9-1c69-40e9-b8e4-d5a03c3c5121" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_July2022GrantsMember_d7b86edc-6cf8-4235-8ae8-edb799ded2af" xlink:href="kwr-20241231.xsd#kwr_July2022GrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:to="loc_kwr_July2022GrantsMember_d7b86edc-6cf8-4235-8ae8-edb799ded2af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_March2022GrantsMember_2bec68a3-ec6f-41b6-bd3e-3d016b159714" xlink:href="kwr-20241231.xsd#kwr_March2022GrantsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:to="loc_kwr_March2022GrantsMember_2bec68a3-ec6f-41b6-bd3e-3d016b159714" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_63a2ddb8-80d1-4162-b04d-51dd39a9b7cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_63a2ddb8-80d1-4162-b04d-51dd39a9b7cf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PerformanceIncentiveStockUnitsMember_639704f8-9554-40bd-8ef2-e845c30b35a5" xlink:href="kwr-20241231.xsd#kwr_PerformanceIncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_535abdb9-7f0a-4d0f-a30d-be45a3533308" xlink:to="loc_kwr_PerformanceIncentiveStockUnitsMember_639704f8-9554-40bd-8ef2-e845c30b35a5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_92cdf2ae-221e-4039-85b3-c492ae8ab267" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_283a3d22-21ed-458a-91fa-4742ecf9d6fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_283a3d22-21ed-458a-91fa-4742ecf9d6fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_d9a31886-34d9-4ef2-a14a-1909398fbff6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_d9a31886-34d9-4ef2-a14a-1909398fbff6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_272145d1-7848-43be-abe5-1137b6fc938f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_272145d1-7848-43be-abe5-1137b6fc938f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_a462bce4-787c-45be-a945-8f697e5ac5c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_a462bce4-787c-45be-a945-8f697e5ac5c0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_69062bd4-fec9-4fe6-b610-8e7ccb778fdc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_3bdee81a-4916-494a-bf3f-78d42e3f7049" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_69062bd4-fec9-4fe6-b610-8e7ccb778fdc" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/EquityActivityofNonvestedAwardsRollforwardDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#EquityActivityofNonvestedAwardsRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/EquityActivityofNonvestedAwardsRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_28565cbc-4c91-4dcc-ad10-6caa45884a1b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_67184949-1275-4f98-918d-25d8a9f64456" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_28565cbc-4c91-4dcc-ad10-6caa45884a1b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_67184949-1275-4f98-918d-25d8a9f64456" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_67184949-1275-4f98-918d-25d8a9f64456" xlink:to="loc_us-gaap_AwardTypeAxis_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e45f459e-670c-49a1-8ca0-c32b75f7d028" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_779cd9bb-ddc4-4e03-8c18-f1f7e98c8806" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e45f459e-670c-49a1-8ca0-c32b75f7d028" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_73b7d2d7-44a6-4a4b-9399-ea3c657ef669" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e45f459e-670c-49a1-8ca0-c32b75f7d028" xlink:to="loc_us-gaap_RestrictedStockMember_73b7d2d7-44a6-4a4b-9399-ea3c657ef669" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_5aec0ce2-8cf4-4ab4-968f-76bc45590006" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e45f459e-670c-49a1-8ca0-c32b75f7d028" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_5aec0ce2-8cf4-4ab4-968f-76bc45590006" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PerformanceIncentiveStockUnitsMember_2e631407-cd03-4c58-a777-dea87968f58d" xlink:href="kwr-20241231.xsd#kwr_PerformanceIncentiveStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e45f459e-670c-49a1-8ca0-c32b75f7d028" xlink:to="loc_kwr_PerformanceIncentiveStockUnitsMember_2e631407-cd03-4c58-a777-dea87968f58d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_28565cbc-4c91-4dcc-ad10-6caa45884a1b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_de799df0-4027-4ac7-8357-8ffbcf87a9d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_de799df0-4027-4ac7-8357-8ffbcf87a9d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_09421e25-f706-4132-a7cd-dbe552e7fb44" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_09421e25-f706-4132-a7cd-dbe552e7fb44" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c212bc1d-8c46-4fd5-853a-7e0f68e2c835" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c212bc1d-8c46-4fd5-853a-7e0f68e2c835" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_6ca5fc42-a52d-4bcf-bbd7-81b3a1e0bf94" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9eb9a729-68b2-4dc6-9bb4-26ff73366cfc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_6ca5fc42-a52d-4bcf-bbd7-81b3a1e0bf94" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_8eef6f8e-7d7d-47aa-8836-049cc681e529" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_28565cbc-4c91-4dcc-ad10-6caa45884a1b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_c3a03887-2ba9-4246-ac3e-586ddaef8767" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_c3a03887-2ba9-4246-ac3e-586ddaef8767" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_32a63218-9e52-48ed-b80f-790dbb3c2393" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_32a63218-9e52-48ed-b80f-790dbb3c2393" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_0f9a15f8-7388-4e04-805a-e5404fa52e36" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_0f9a15f8-7388-4e04-805a-e5404fa52e36" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f5747718-16cf-4f75-9a38-61d25e6f1d11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_acdda701-9238-4f38-906e-715468ef0432" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f5747718-16cf-4f75-9a38-61d25e6f1d11" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_29aa0381-eb5b-4de5-902b-21060916b370" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExaminationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationTable_06da5c80-0f5b-4775-b47a-2aa65ffd43c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxExaminationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_IncomeTaxExaminationTable_06da5c80-0f5b-4775-b47a-2aa65ffd43c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_321e4b4f-3b6a-430a-ab95-a6e639dc7407" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_06da5c80-0f5b-4775-b47a-2aa65ffd43c3" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_321e4b4f-3b6a-430a-ab95-a6e639dc7407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_321e4b4f-3b6a-430a-ab95-a6e639dc7407_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_321e4b4f-3b6a-430a-ab95-a6e639dc7407" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_321e4b4f-3b6a-430a-ab95-a6e639dc7407_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_7786f488-afd1-4b54-a837-ef5c0e991a86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_321e4b4f-3b6a-430a-ab95-a6e639dc7407" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_7786f488-afd1-4b54-a837-ef5c0e991a86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_982f150e-e717-4830-b73b-49eca9c833eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_7786f488-afd1-4b54-a837-ef5c0e991a86" xlink:to="loc_us-gaap_ForeignCountryMember_982f150e-e717-4830-b73b-49eca9c833eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_LossCarryforwardExpirationAxis_363bf7c8-db80-4fc0-be4c-64b840bcb137" xlink:href="kwr-20241231.xsd#kwr_LossCarryforwardExpirationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_06da5c80-0f5b-4775-b47a-2aa65ffd43c3" xlink:to="loc_kwr_LossCarryforwardExpirationAxis_363bf7c8-db80-4fc0-be4c-64b840bcb137" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_LossCarryforwardExpirationDomain_363bf7c8-db80-4fc0-be4c-64b840bcb137_default" xlink:href="kwr-20241231.xsd#kwr_LossCarryforwardExpirationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_kwr_LossCarryforwardExpirationAxis_363bf7c8-db80-4fc0-be4c-64b840bcb137" xlink:to="loc_kwr_LossCarryforwardExpirationDomain_363bf7c8-db80-4fc0-be4c-64b840bcb137_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_LossCarryforwardExpirationDomain_efb65d5b-2a42-4060-ad67-29e4cf16a5a1" xlink:href="kwr-20241231.xsd#kwr_LossCarryforwardExpirationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_kwr_LossCarryforwardExpirationAxis_363bf7c8-db80-4fc0-be4c-64b840bcb137" xlink:to="loc_kwr_LossCarryforwardExpirationDomain_efb65d5b-2a42-4060-ad67-29e4cf16a5a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ExpirationInYearFiveMember_b419859b-2333-41b0-a424-d017147abf22" xlink:href="kwr-20241231.xsd#kwr_ExpirationInYearFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kwr_LossCarryforwardExpirationDomain_efb65d5b-2a42-4060-ad67-29e4cf16a5a1" xlink:to="loc_kwr_ExpirationInYearFiveMember_b419859b-2333-41b0-a424-d017147abf22" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ExpirationInTwentyYearsMember_98c70725-4b01-4f8e-959e-2a4b06a56421" xlink:href="kwr-20241231.xsd#kwr_ExpirationInTwentyYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_kwr_LossCarryforwardExpirationDomain_efb65d5b-2a42-4060-ad67-29e4cf16a5a1" xlink:to="loc_kwr_ExpirationInTwentyYearsMember_98c70725-4b01-4f8e-959e-2a4b06a56421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiability_077a6b38-9a0b-4ff4-8772-877aadfe9457" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiability_077a6b38-9a0b-4ff4-8772-877aadfe9457" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityInstallmentsPaid_c915dd18-c5fa-4583-9343-0d6b5cd37511" xlink:href="kwr-20241231.xsd#kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityInstallmentsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityInstallmentsPaid_c915dd18-c5fa-4583-9343-0d6b5cd37511" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityRemainingInstallments_ec63a071-a1de-4d8e-9bdb-d1a5b2678c7c" xlink:href="kwr-20241231.xsd#kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityRemainingInstallments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsLiabilityRemainingInstallments_ec63a071-a1de-4d8e-9bdb-d1a5b2678c7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilities_62c6dbcd-140d-443b-845e-3193e3547698" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_DeferredTaxLiabilities_62c6dbcd-140d-443b-845e-3193e3547698" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_Taxcutsandjobsactof2017accountingearningsofforeignsubsidiary_9c78d900-2b84-46f7-8f44-b92c26675da6" xlink:href="kwr-20241231.xsd#kwr_Taxcutsandjobsactof2017accountingearningsofforeignsubsidiary"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_Taxcutsandjobsactof2017accountingearningsofforeignsubsidiary_9c78d900-2b84-46f7-8f44-b92c26675da6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal_5f41d5a9-0f4b-4def-a2be-bb04055e1b6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal_5f41d5a9-0f4b-4def-a2be-bb04055e1b6a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalBasedOnReversalOfDeferredTaxLiabilities_c26e8ea1-e473-4abd-9677-88c7b3dc3e24" xlink:href="kwr-20241231.xsd#kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalBasedOnReversalOfDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalBasedOnReversalOfDeferredTaxLiabilities_c26e8ea1-e473-4abd-9677-88c7b3dc3e24" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OperatingLossCarryforwardsStatePartialValuationAllowance_f8da557c-0d54-4a42-af6b-c49f1bede5a5" xlink:href="kwr-20241231.xsd#kwr_OperatingLossCarryforwardsStatePartialValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_OperatingLossCarryforwardsStatePartialValuationAllowance_f8da557c-0d54-4a42-af6b-c49f1bede5a5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalExpirationPeriod_fe282aa3-a7cf-442f-a654-2409ff75e5c7" xlink:href="kwr-20241231.xsd#kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocalExpirationPeriod_fe282aa3-a7cf-442f-a654-2409ff75e5c7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ValuationAllowanceAmountStateDeferredTaxAsset_a956785e-35de-456e-a033-aad6b21233a5" xlink:href="kwr-20241231.xsd#kwr_ValuationAllowanceAmountStateDeferredTaxAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_ValuationAllowanceAmountStateDeferredTaxAsset_a956785e-35de-456e-a033-aad6b21233a5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign_df3e36c5-9d29-44d5-81dc-35a61354b321" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign_df3e36c5-9d29-44d5-81dc-35a61354b321" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OperatingLossCarryforwardsForeignPartialValuationAllowance_adc70f3c-fcc7-48e1-b8ef-b8842f37397d" xlink:href="kwr-20241231.xsd#kwr_OperatingLossCarryforwardsForeignPartialValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_OperatingLossCarryforwardsForeignPartialValuationAllowance_adc70f3c-fcc7-48e1-b8ef-b8842f37397d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignNet_282314a8-aae4-44f9-8940-94f9b8c87885" xlink:href="kwr-20241231.xsd#kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignNet_282314a8-aae4-44f9-8940-94f9b8c87885" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ValuationAllowanceAmountOtherForeignDeferredTaxAsset_94f86445-4e84-4a88-b213-b47338c00ec3" xlink:href="kwr-20241231.xsd#kwr_ValuationAllowanceAmountOtherForeignDeferredTaxAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_ValuationAllowanceAmountOtherForeignDeferredTaxAsset_94f86445-4e84-4a88-b213-b47338c00ec3" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignExpirationPeriod_b9e1a52c-1bc0-478a-af02-1207cd7c5915" xlink:href="kwr-20241231.xsd#kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_DeferredTaxAssetsOperatingLossCarryforwardsForeignExpirationPeriod_b9e1a52c-1bc0-478a-af02-1207cd7c5915" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DeferredTaxAssetsTaxCreditCarryforwardsForeignExpectedToExpire_7d8ab4f2-f483-465e-a555-dfabe7653aeb" xlink:href="kwr-20241231.xsd#kwr_DeferredTaxAssetsTaxCreditCarryforwardsForeignExpectedToExpire"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_DeferredTaxAssetsTaxCreditCarryforwardsForeignExpectedToExpire_7d8ab4f2-f483-465e-a555-dfabe7653aeb" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsValuationAllowance_c2714397-edd9-4b5f-9b4b-85a8456e507a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_OperatingLossCarryforwardsValuationAllowance_c2714397-edd9-4b5f-9b4b-85a8456e507a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_8c65ed5f-ca25-463f-a8f2-c05324704bde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_8c65ed5f-ca25-463f-a8f2-c05324704bde" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued_e3c9195a-3f31-4006-95cf-7ce32ea2b46e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued_e3c9195a-3f31-4006-95cf-7ce32ea2b46e" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued_bea643c5-f37a-4cbd-9fba-8e104f0cc5c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued_bea643c5-f37a-4cbd-9fba-8e104f0cc5c3" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense_ce56f49b-a999-410b-98b4-0d55b722fb4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesExpense_ce56f49b-a999-410b-98b4-0d55b722fb4d" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense_5f8c1808-d011-47a4-97d9-9038ecf912bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesExpense_5f8c1808-d011-47a4-97d9-9038ecf912bc" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_74c91071-f206-45c1-89d8-7962e7874256" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_74c91071-f206-45c1-89d8-7962e7874256" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_UnrecognizedTaxBenefitsIfRecognized_1413978b-ad97-4981-a324-9f3d2deee91f" xlink:href="kwr-20241231.xsd#kwr_UnrecognizedTaxBenefitsIfRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_33f0bf5e-8c36-43ed-95fa-15d34408091d" xlink:to="loc_kwr_UnrecognizedTaxBenefitsIfRecognized_1413978b-ad97-4981-a324-9f3d2deee91f" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_ab4c4c84-a255-402d-b4bd-0b2673f1b1b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_ab4c4c84-a255-402d-b4bd-0b2673f1b1b4" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_46f8b7e4-48f0-47a0-957f-19e28e761d0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_46f8b7e4-48f0-47a0-957f-19e28e761d0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_46f8b7e4-48f0-47a0-957f-19e28e761d0c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_46f8b7e4-48f0-47a0-957f-19e28e761d0c" xlink:to="loc_us-gaap_SegmentDomain_46f8b7e4-48f0-47a0-957f-19e28e761d0c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_0c1666c4-a003-4dd8-8408-c4a83569dcbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_46f8b7e4-48f0-47a0-957f-19e28e761d0c" xlink:to="loc_us-gaap_SegmentDomain_0c1666c4-a003-4dd8-8408-c4a83569dcbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_GlobalSpecialtyBusinessesMember_f2098c6e-9723-4355-9c64-5b9a773ea69e" xlink:href="kwr-20241231.xsd#kwr_GlobalSpecialtyBusinessesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_0c1666c4-a003-4dd8-8408-c4a83569dcbc" xlink:to="loc_kwr_GlobalSpecialtyBusinessesMember_f2098c6e-9723-4355-9c64-5b9a773ea69e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:to="loc_srt_ConsolidationItemsAxis_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1" xlink:to="loc_srt_ConsolidationItemsDomain_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_fab4a8ba-3cb3-41d3-b7ac-ee21842dd3ff" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_2cc7ddfd-de09-4f58-a0f5-3d6a4cb2ced1" xlink:to="loc_srt_ConsolidationItemsDomain_fab4a8ba-3cb3-41d3-b7ac-ee21842dd3ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_242b5eba-dafb-41b6-8bff-9a15298c96a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_fab4a8ba-3cb3-41d3-b7ac-ee21842dd3ff" xlink:to="loc_us-gaap_OperatingSegmentsMember_242b5eba-dafb-41b6-8bff-9a15298c96a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_137a2026-4c82-457d-ba68-31740bdb8401" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:to="loc_srt_RestatementAxis_137a2026-4c82-457d-ba68-31740bdb8401" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_137a2026-4c82-457d-ba68-31740bdb8401_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_137a2026-4c82-457d-ba68-31740bdb8401" xlink:to="loc_srt_RestatementDomain_137a2026-4c82-457d-ba68-31740bdb8401_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_ecedbe47-1a07-4cc7-8ffa-bffb237a96f1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_137a2026-4c82-457d-ba68-31740bdb8401" xlink:to="loc_srt_RestatementDomain_ecedbe47-1a07-4cc7-8ffa-bffb237a96f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioPreviouslyReportedMember_4e61668e-aec0-4470-b52a-79fef32913d7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScenarioPreviouslyReportedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_ecedbe47-1a07-4cc7-8ffa-bffb237a96f1" xlink:to="loc_srt_ScenarioPreviouslyReportedMember_4e61668e-aec0-4470-b52a-79fef32913d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_89468899-6889-4967-bba6-20e7e7d08eac" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RevisionOfPriorPeriodReclassificationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_ecedbe47-1a07-4cc7-8ffa-bffb237a96f1" xlink:to="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_89468899-6889-4967-bba6-20e7e7d08eac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_31f3271d-3fae-40d3-82b7-10e1342f8159" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_b75afe9b-cadd-4b5a-b32f-d9e0c690f557" xlink:to="loc_srt_StatementGeographicalAxis_31f3271d-3fae-40d3-82b7-10e1342f8159" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_31f3271d-3fae-40d3-82b7-10e1342f8159_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_31f3271d-3fae-40d3-82b7-10e1342f8159" xlink:to="loc_srt_SegmentGeographicalDomain_31f3271d-3fae-40d3-82b7-10e1342f8159_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_20d36d59-5aac-4236-ada1-291e50f69065" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_31f3271d-3fae-40d3-82b7-10e1342f8159" xlink:to="loc_srt_SegmentGeographicalDomain_20d36d59-5aac-4236-ada1-291e50f69065" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_7d7d038d-09da-4b82-8edc-0bfd46a9b283" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_20d36d59-5aac-4236-ada1-291e50f69065" xlink:to="loc_srt_AmericasMember_7d7d038d-09da-4b82-8edc-0bfd46a9b283" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_bf8b2e3b-1a90-47ad-8b98-71e9812ecd2f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_20d36d59-5aac-4236-ada1-291e50f69065" xlink:to="loc_us-gaap_EMEAMember_bf8b2e3b-1a90-47ad-8b98-71e9812ecd2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_297d6e67-1a68-4d10-9cb6-145e9cd449fc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_20d36d59-5aac-4236-ada1-291e50f69065" xlink:to="loc_srt_AsiaPacificMember_297d6e67-1a68-4d10-9cb6-145e9cd449fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ab4c4c84-a255-402d-b4bd-0b2673f1b1b4" xlink:to="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_005f350f-bcaf-40fb-a4df-3e1c767eacfb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:to="loc_us-gaap_Goodwill_005f350f-bcaf-40fb-a4df-3e1c767eacfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_GoodwillReallocationOfReportingUnits_a365fdcb-4763-4538-a12a-6b8dcd8058f4" xlink:href="kwr-20241231.xsd#kwr_GoodwillReallocationOfReportingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:to="loc_kwr_GoodwillReallocationOfReportingUnits_a365fdcb-4763-4538-a12a-6b8dcd8058f4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_46ecbc69-1354-4789-91b8-a592efb42174" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_46ecbc69-1354-4789-91b8-a592efb42174" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_5bc551b1-9f65-43c3-9cae-fc87461db66d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_65569b56-2d7d-4d48-a1c5-a069470317f7" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_5bc551b1-9f65-43c3-9cae-fc87461db66d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_b6523546-436f-4153-b720-c35f53bb2a1f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillGross_eebdf2ed-efd0-4912-b3a5-641604a1428b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ab4c4c84-a255-402d-b4bd-0b2673f1b1b4" xlink:to="loc_us-gaap_GoodwillGross_eebdf2ed-efd0-4912-b3a5-641604a1428b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_8d8938a3-3241-4adf-8d28-bcbf83254385" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ab4c4c84-a255-402d-b4bd-0b2673f1b1b4" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_8d8938a3-3241-4adf-8d28-bcbf83254385" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_7dacb7b0-eef7-47c8-aedc-da482944a493" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/GoodwillandOtherIntangibleAssetsIntangibleAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#GoodwillandOtherIntangibleAssetsIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/GoodwillandOtherIntangibleAssetsIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9b2a3988-491e-47f5-8b24-cd1ee2a68d05" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_78cf2cd2-16f6-4226-a465-7ed6d41e42da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9b2a3988-491e-47f5-8b24-cd1ee2a68d05" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_78cf2cd2-16f6-4226-a465-7ed6d41e42da" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_e6357a7c-bd90-4ebd-9a03-8475fee67c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_78cf2cd2-16f6-4226-a465-7ed6d41e42da" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_e6357a7c-bd90-4ebd-9a03-8475fee67c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e6357a7c-bd90-4ebd-9a03-8475fee67c6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_e6357a7c-bd90-4ebd-9a03-8475fee67c6f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_e6357a7c-bd90-4ebd-9a03-8475fee67c6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_33284c00-3cf8-4b86-97d1-dd7c8c1cbfb4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_e6357a7c-bd90-4ebd-9a03-8475fee67c6f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_33284c00-3cf8-4b86-97d1-dd7c8c1cbfb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerListsMember_132c9832-b211-45b8-904f-fba2a48aa620" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerListsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_33284c00-3cf8-4b86-97d1-dd7c8c1cbfb4" xlink:to="loc_us-gaap_CustomerListsMember_132c9832-b211-45b8-904f-fba2a48aa620" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_TrademarksFormulationsAndProductTechnologyMember_5c3541a8-2ac9-4a01-8d05-0d8db52df6bb" xlink:href="kwr-20241231.xsd#kwr_TrademarksFormulationsAndProductTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_33284c00-3cf8-4b86-97d1-dd7c8c1cbfb4" xlink:to="loc_kwr_TrademarksFormulationsAndProductTechnologyMember_5c3541a8-2ac9-4a01-8d05-0d8db52df6bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_106b0cb7-12d5-4717-a51e-ed494f55f51d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_33284c00-3cf8-4b86-97d1-dd7c8c1cbfb4" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_106b0cb7-12d5-4717-a51e-ed494f55f51d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_254aeb57-7d09-4c92-a2ab-a474e954457d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9b2a3988-491e-47f5-8b24-cd1ee2a68d05" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_254aeb57-7d09-4c92-a2ab-a474e954457d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_a104cda7-8a7a-4515-82fc-30f5c03b9ea7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9b2a3988-491e-47f5-8b24-cd1ee2a68d05" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_a104cda7-8a7a-4515-82fc-30f5c03b9ea7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_097e0d92-03c1-4bff-8725-968b13fce7d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_9b2a3988-491e-47f5-8b24-cd1ee2a68d05" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_097e0d92-03c1-4bff-8725-968b13fce7d2" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/InvestmentinAssociatedCompaniesNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#InvestmentinAssociatedCompaniesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/InvestmentinAssociatedCompaniesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d67e43b8-7a3c-46de-a2fb-398690b0a195" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_5b76b58b-c715-49f3-85b2-69cbb84fc0c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d67e43b8-7a3c-46de-a2fb-398690b0a195" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_5b76b58b-c715-49f3-85b2-69cbb84fc0c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_292010d4-56bc-4e35-92ad-b3e85f9d8981" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_5b76b58b-c715-49f3-85b2-69cbb84fc0c3" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_292010d4-56bc-4e35-92ad-b3e85f9d8981" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_292010d4-56bc-4e35-92ad-b3e85f9d8981_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_292010d4-56bc-4e35-92ad-b3e85f9d8981" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_292010d4-56bc-4e35-92ad-b3e85f9d8981_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_292010d4-56bc-4e35-92ad-b3e85f9d8981" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNameHoughtonKoreaMember_ae84c1d6-1b50-4305-9ba2-1061db425ddd" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNameHoughtonKoreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:to="loc_kwr_EquityMethodInvesteeNameHoughtonKoreaMember_ae84c1d6-1b50-4305-9ba2-1061db425ddd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNameNipponQuakerJapanMember_43d24a42-23c6-4e4f-9040-feebcb863260" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNameNipponQuakerJapanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:to="loc_kwr_EquityMethodInvesteeNameNipponQuakerJapanMember_43d24a42-23c6-4e4f-9040-feebcb863260" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNameKelkoPanamaMember_87e8edcb-da65-40d4-ae70-3c398f1cfa4a" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNameKelkoPanamaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:to="loc_kwr_EquityMethodInvesteeNameKelkoPanamaMember_87e8edcb-da65-40d4-ae70-3c398f1cfa4a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNamePrimexMember_cb17a5c8-3845-40bb-9997-a2e790839a55" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNamePrimexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_090f9553-f79a-47c1-abf9-d5f52575b5ba" xlink:to="loc_kwr_EquityMethodInvesteeNamePrimexMember_cb17a5c8-3845-40bb-9997-a2e790839a55" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_71d58783-6e5b-451c-b457-f649e702fb0b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_5b76b58b-c715-49f3-85b2-69cbb84fc0c3" xlink:to="loc_srt_StatementGeographicalAxis_71d58783-6e5b-451c-b457-f649e702fb0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_71d58783-6e5b-451c-b457-f649e702fb0b_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_71d58783-6e5b-451c-b457-f649e702fb0b" xlink:to="loc_srt_SegmentGeographicalDomain_71d58783-6e5b-451c-b457-f649e702fb0b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_48fb6e0e-dead-4127-9e39-f3a0011e48da" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_71d58783-6e5b-451c-b457-f649e702fb0b" xlink:to="loc_srt_SegmentGeographicalDomain_48fb6e0e-dead-4127-9e39-f3a0011e48da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_7d33073c-06e4-4367-a33b-45602fc35084" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_48fb6e0e-dead-4127-9e39-f3a0011e48da" xlink:to="loc_srt_AmericasMember_7d33073c-06e4-4367-a33b-45602fc35084" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_d0bc1f61-4ea5-4323-80de-f7c0fed05a2e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_48fb6e0e-dead-4127-9e39-f3a0011e48da" xlink:to="loc_srt_AsiaPacificMember_d0bc1f61-4ea5-4323-80de-f7c0fed05a2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_7d0f99ce-2c03-460f-9dcd-e2c25ca6ef6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d67e43b8-7a3c-46de-a2fb-398690b0a195" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_7d0f99ce-2c03-460f-9dcd-e2c25ca6ef6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_bb101b94-0779-47d5-8b52-9e656c394238" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d67e43b8-7a3c-46de-a2fb-398690b0a195" xlink:to="loc_us-gaap_EquityMethodInvestments_bb101b94-0779-47d5-8b52-9e656c394238" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_0e95d49a-db90-4c55-98f4-6d360f28ac32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsLineItems_d67e43b8-7a3c-46de-a2fb-398690b0a195" xlink:to="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_0e95d49a-db90-4c55-98f4-6d360f28ac32" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/InvestmentsinAssociatedCompaniesSummarizedFinancialInformationDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#InvestmentsinAssociatedCompaniesSummarizedFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/InvestmentsinAssociatedCompaniesSummarizedFinancialInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_afdd08b8-7f67-4cba-9846-7c85fd27c019" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_cbcdac5b-73ad-43a6-8929-68dfc28e2c2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEquityMethodInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_afdd08b8-7f67-4cba-9846-7c85fd27c019" xlink:to="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_cbcdac5b-73ad-43a6-8929-68dfc28e2c2e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d7f13fad-b98b-4402-9c6b-3c7607eb03b7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEquityMethodInvestmentsTable_cbcdac5b-73ad-43a6-8929-68dfc28e2c2e" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d7f13fad-b98b-4402-9c6b-3c7607eb03b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_d7f13fad-b98b-4402-9c6b-3c7607eb03b7_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d7f13fad-b98b-4402-9c6b-3c7607eb03b7" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_d7f13fad-b98b-4402-9c6b-3c7607eb03b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d7f13fad-b98b-4402-9c6b-3c7607eb03b7" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_KoreaHoughtonCoporationMember_d4a86913-affe-484d-b6df-70098a707f07" xlink:href="kwr-20241231.xsd#kwr_KoreaHoughtonCoporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:to="loc_kwr_KoreaHoughtonCoporationMember_d4a86913-affe-484d-b6df-70098a707f07" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNameNipponQuakerJapanMember_25ad5e07-ea63-4316-8baa-a88a4b6ad52a" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNameNipponQuakerJapanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:to="loc_kwr_EquityMethodInvesteeNameNipponQuakerJapanMember_25ad5e07-ea63-4316-8baa-a88a4b6ad52a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNameKelkoPanamaMember_edeacd66-7186-426b-8c06-ad6b578b29fc" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNameKelkoPanamaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:to="loc_kwr_EquityMethodInvesteeNameKelkoPanamaMember_edeacd66-7186-426b-8c06-ad6b578b29fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityMethodInvesteeNamePrimexMember_24c03cd8-692b-4207-af06-35ae55875cbb" xlink:href="kwr-20241231.xsd#kwr_EquityMethodInvesteeNamePrimexMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_1dd493bc-8498-4f51-b75c-204e5626f600" xlink:to="loc_kwr_EquityMethodInvesteeNamePrimexMember_24c03cd8-692b-4207-af06-35ae55875cbb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_e9934d54-9c75-4063-b6e5-e6c7d3197cb5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_afdd08b8-7f67-4cba-9846-7c85fd27c019" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_e9934d54-9c75-4063-b6e5-e6c7d3197cb5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/OtherNonCurrentAssetsScheduleofOtherAssetsNoncurrentDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#OtherNonCurrentAssetsScheduleofOtherAssetsNoncurrentDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/OtherNonCurrentAssetsScheduleofOtherAssetsNoncurrentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f7e9b53a-9d60-4907-92dc-c89b6fa09c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f7e9b53a-9d60-4907-92dc-c89b6fa09c5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_d75f545c-f2de-4cd4-a699-10405fe42e29" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_f7e9b53a-9d60-4907-92dc-c89b6fa09c5c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_d75f545c-f2de-4cd4-a699-10405fe42e29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d75f545c-f2de-4cd4-a699-10405fe42e29_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d75f545c-f2de-4cd4-a699-10405fe42e29" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d75f545c-f2de-4cd4-a699-10405fe42e29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_de562f22-0e48-42f1-9c1d-5278eba080e3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d75f545c-f2de-4cd4-a699-10405fe42e29" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_de562f22-0e48-42f1-9c1d-5278eba080e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_HoughtonMember_7eb03129-8b19-49cc-8bb9-fa94a3312cdf" xlink:href="kwr-20241231.xsd#kwr_HoughtonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_de562f22-0e48-42f1-9c1d-5278eba080e3" xlink:to="loc_kwr_HoughtonMember_7eb03129-8b19-49cc-8bb9-fa94a3312cdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_UncertainTaxPositionAssetsNonCurrent_68785e02-92c8-497e-acb7-5ca322646ab8" xlink:href="kwr-20241231.xsd#kwr_UncertainTaxPositionAssetsNonCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_kwr_UncertainTaxPositionAssetsNonCurrent_68785e02-92c8-497e-acb7-5ca322646ab8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_ba635c14-e49f-4c49-8f31-517c156e85c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_ba635c14-e49f-4c49-8f31-517c156e85c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_bdd84151-2a87-452b-ae1f-ce95b0dc1d80" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_bdd84151-2a87-452b-ae1f-ce95b0dc1d80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent_217a3523-d89b-4355-882a-2e0743d585be" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_DerivativeAssetsNoncurrent_217a3523-d89b-4355-882a-2e0743d585be" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestmentsAndReceivablesNet_743a3855-4c1b-44fc-9cf6-56b4003c3564" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermInvestmentsAndReceivablesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_LongTermInvestmentsAndReceivablesNet_743a3855-4c1b-44fc-9cf6-56b4003c3564" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsHeldInTrustCurrent_4d02daf8-e59f-4db3-8515-009ab85fff9a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsHeldInTrustCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_AssetsHeldInTrustCurrent_4d02daf8-e59f-4db3-8515-009ab85fff9a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_dfca0b90-b5c5-4ba4-800f-f73dcc53b8d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_dfca0b90-b5c5-4ba4-800f-f73dcc53b8d3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashSurrenderValueOfLifeInsurance_bf03ac25-4251-42fc-bb4b-1fe2876151c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashSurrenderValueOfLifeInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_CashSurrenderValueOfLifeInsurance_bf03ac25-4251-42fc-bb4b-1fe2876151c1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_f80fc980-1c1a-4fd4-9f37-5d43fddcbfa9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_OtherAssetsMiscellaneousNoncurrent_f80fc980-1c1a-4fd4-9f37-5d43fddcbfa9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_e104052b-14a7-4f3c-9757-7b3aff228b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_4b0e9313-9492-4fa2-9a7d-7be70603fefd" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_e104052b-14a7-4f3c-9757-7b3aff228b1e" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/DebtScheduleofDebtDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#DebtScheduleofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/DebtScheduleofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_d3e78056-ffe5-45d2-ab74-35c3bde1af9a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_DebtInstrumentTable_d3e78056-ffe5-45d2-ab74-35c3bde1af9a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_f2acace5-065c-4855-b921-5fd6f130b457" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d3e78056-ffe5-45d2-ab74-35c3bde1af9a" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_f2acace5-065c-4855-b921-5fd6f130b457" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f2acace5-065c-4855-b921-5fd6f130b457_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f2acace5-065c-4855-b921-5fd6f130b457" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f2acace5-065c-4855-b921-5fd6f130b457_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f2acace5-065c-4855-b921-5fd6f130b457" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedRevolverMember_e3719681-424c-4603-8569-7d35dbbd2e8a" xlink:href="kwr-20241231.xsd#kwr_AmendedRevolverMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:to="loc_kwr_AmendedRevolverMember_e3719681-424c-4603-8569-7d35dbbd2e8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedUsTermLoanMember_bb272a19-702d-41e7-be4f-538306c64f08" xlink:href="kwr-20241231.xsd#kwr_AmendedUsTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:to="loc_kwr_AmendedUsTermLoanMember_bb272a19-702d-41e7-be4f-538306c64f08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedEuroTermLoanMember_65ed1b84-c975-4838-8961-b75b4829a46e" xlink:href="kwr-20241231.xsd#kwr_AmendedEuroTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:to="loc_kwr_AmendedEuroTermLoanMember_65ed1b84-c975-4838-8961-b75b4829a46e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_IndustrialDevelopmentBondsMember_3db305c8-5674-48d7-b001-7f34d1c263ad" xlink:href="kwr-20241231.xsd#kwr_IndustrialDevelopmentBondsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:to="loc_kwr_IndustrialDevelopmentBondsMember_3db305c8-5674-48d7-b001-7f34d1c263ad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_BankLinesOfCreditAndOtherDebtObligationsMember_a83aa9c0-2e6d-4696-9bbb-167d2d196f18" xlink:href="kwr-20241231.xsd#kwr_BankLinesOfCreditAndOtherDebtObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1050e7d7-d212-4832-8aa2-5fd8887a2147" xlink:to="loc_kwr_BankLinesOfCreditAndOtherDebtObligationsMember_a83aa9c0-2e6d-4696-9bbb-167d2d196f18" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1c7ff435-ba83-42d7-809a-1087ed047aaa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_1c7ff435-ba83-42d7-809a-1087ed047aaa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_ee5da857-13f9-4b77-ad33-fe6354576b9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_ee5da857-13f9-4b77-ad33-fe6354576b9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_3112cc66-239a-4c98-b574-736ae2277e0a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_3112cc66-239a-4c98-b574-736ae2277e0a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_373bfc0d-707f-4efb-b647-fd6743b33763" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_ShortTermBorrowings_373bfc0d-707f-4efb-b647-fd6743b33763" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_45823e7d-19c4-498b-8e9a-75e7bd991e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_48ef8fef-0368-46c3-881e-23ecc553c48b" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_45823e7d-19c4-498b-8e9a-75e7bd991e9c" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_3c8c40bd-b5ef-4680-ab21-426fa40d9c70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_3c8c40bd-b5ef-4680-ab21-426fa40d9c70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3c8c40bd-b5ef-4680-ab21-426fa40d9c70_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3c8c40bd-b5ef-4680-ab21-426fa40d9c70" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3c8c40bd-b5ef-4680-ab21-426fa40d9c70_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_3c8c40bd-b5ef-4680-ab21-426fa40d9c70" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedEuroTermLoanMember_d67af791-e3e0-4edf-b438-f06c6f23cde0" xlink:href="kwr-20241231.xsd#kwr_AmendedEuroTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_AmendedEuroTermLoanMember_d67af791-e3e0-4edf-b438-f06c6f23cde0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedUsTermLoanMember_8eaf8519-d79f-405a-862e-39f3adc5ea3e" xlink:href="kwr-20241231.xsd#kwr_AmendedUsTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_AmendedUsTermLoanMember_8eaf8519-d79f-405a-862e-39f3adc5ea3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedRevolverMember_ed001920-004c-4970-9408-edecca919965" xlink:href="kwr-20241231.xsd#kwr_AmendedRevolverMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_AmendedRevolverMember_ed001920-004c-4970-9408-edecca919965" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmendedCreditFacilityMember_28cf1ff0-648f-4b89-8fa4-e902ea75cdc3" xlink:href="kwr-20241231.xsd#kwr_AmendedCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_AmendedCreditFacilityMember_28cf1ff0-648f-4b89-8fa4-e902ea75cdc3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_31cf2700-2928-42da-ab67-921d0cae06c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_us-gaap_LineOfCreditMember_31cf2700-2928-42da-ab67-921d0cae06c6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OriginalCreditFacilityAndTheAmendedCreditFacilityMember_034c1e8b-6775-471e-b40a-f9c5295443a7" xlink:href="kwr-20241231.xsd#kwr_OriginalCreditFacilityAndTheAmendedCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_OriginalCreditFacilityAndTheAmendedCreditFacilityMember_034c1e8b-6775-471e-b40a-f9c5295443a7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OldCreditFacilityMember_d8a53a37-f361-4e44-a4fd-6a5ef982b7ff" xlink:href="kwr-20241231.xsd#kwr_OldCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_kwr_OldCreditFacilityMember_d8a53a37-f361-4e44-a4fd-6a5ef982b7ff" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_b19ea940-756f-4034-9870-81e830c18eed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_b19ea940-756f-4034-9870-81e830c18eed" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticLineOfCreditMember_eaa2d8e5-0bd0-4bbf-b3d1-0ec3b1f993b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticLineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_us-gaap_DomesticLineOfCreditMember_eaa2d8e5-0bd0-4bbf-b3d1-0ec3b1f993b1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateBondSecuritiesMember_f0eac58b-c33c-4c13-be27-8d022a3a9dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CorporateBondSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_4fe640de-6962-417c-840e-5bde11061144" xlink:to="loc_us-gaap_CorporateBondSecuritiesMember_f0eac58b-c33c-4c13-be27-8d022a3a9dc6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_c9a56ab9-f96f-43c6-835e-ed160552ace0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_srt_RangeAxis_c9a56ab9-f96f-43c6-835e-ed160552ace0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c9a56ab9-f96f-43c6-835e-ed160552ace0_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_c9a56ab9-f96f-43c6-835e-ed160552ace0" xlink:to="loc_srt_RangeMember_c9a56ab9-f96f-43c6-835e-ed160552ace0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e0a9143d-cc0c-4eed-be2f-29a3fc6e69a2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_c9a56ab9-f96f-43c6-835e-ed160552ace0" xlink:to="loc_srt_RangeMember_e0a9143d-cc0c-4eed-be2f-29a3fc6e69a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_546f6989-b211-4af7-89d7-d26b7c5cb2d5" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e0a9143d-cc0c-4eed-be2f-29a3fc6e69a2" xlink:to="loc_srt_MinimumMember_546f6989-b211-4af7-89d7-d26b7c5cb2d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_27274b66-0cb4-428d-ac77-bb76f80ca2f8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e0a9143d-cc0c-4eed-be2f-29a3fc6e69a2" xlink:to="loc_srt_MaximumMember_27274b66-0cb4-428d-ac77-bb76f80ca2f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_79f41d8d-cf36-4064-aaac-5d8c2112bf3a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_us-gaap_VariableRateAxis_79f41d8d-cf36-4064-aaac-5d8c2112bf3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_79f41d8d-cf36-4064-aaac-5d8c2112bf3a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_79f41d8d-cf36-4064-aaac-5d8c2112bf3a" xlink:to="loc_us-gaap_VariableRateDomain_79f41d8d-cf36-4064-aaac-5d8c2112bf3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_f6e2e568-b80c-4a80-b243-85e497f1bdcc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_79f41d8d-cf36-4064-aaac-5d8c2112bf3a" xlink:to="loc_us-gaap_VariableRateDomain_f6e2e568-b80c-4a80-b243-85e497f1bdcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_BaseRateLoansRateMember_7c5ba9f1-34f7-44ea-b460-1c52621bd943" xlink:href="kwr-20241231.xsd#kwr_BaseRateLoansRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_f6e2e568-b80c-4a80-b243-85e497f1bdcc" xlink:to="loc_kwr_BaseRateLoansRateMember_7c5ba9f1-34f7-44ea-b460-1c52621bd943" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AlternativeCurrencyTermRatePlusTheApplicableRateMember_c1039427-5498-4b74-878b-b5b65079f6a2" xlink:href="kwr-20241231.xsd#kwr_AlternativeCurrencyTermRatePlusTheApplicableRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_f6e2e568-b80c-4a80-b243-85e497f1bdcc" xlink:to="loc_kwr_AlternativeCurrencyTermRatePlusTheApplicableRateMember_c1039427-5498-4b74-878b-b5b65079f6a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_9a0d1dbc-d884-43fc-8e39-5af23c3a22a9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_f6e2e568-b80c-4a80-b243-85e497f1bdcc" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_9a0d1dbc-d884-43fc-8e39-5af23c3a22a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_3de745e5-40a6-402d-b126-a36a6f14da62" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_3de745e5-40a6-402d-b126-a36a6f14da62" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_3de745e5-40a6-402d-b126-a36a6f14da62_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_3de745e5-40a6-402d-b126-a36a6f14da62" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_3de745e5-40a6-402d-b126-a36a6f14da62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_ec71b75f-4976-4425-a02d-a4b09414004b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_3de745e5-40a6-402d-b126-a36a6f14da62" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_ec71b75f-4976-4425-a02d-a4b09414004b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_5ad8c936-1dab-484d-9dc5-f4ebcdc575aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_ec71b75f-4976-4425-a02d-a4b09414004b" xlink:to="loc_us-gaap_LetterOfCreditMember_5ad8c936-1dab-484d-9dc5-f4ebcdc575aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_b4f180ed-330a-4b71-862e-c2ffd24c8fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_b4f180ed-330a-4b71-862e-c2ffd24c8fd3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_b4f180ed-330a-4b71-862e-c2ffd24c8fd3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_b4f180ed-330a-4b71-862e-c2ffd24c8fd3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_b4f180ed-330a-4b71-862e-c2ffd24c8fd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_260714fc-d2e8-4992-aa0d-f893b2632ea6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_b4f180ed-330a-4b71-862e-c2ffd24c8fd3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_260714fc-d2e8-4992-aa0d-f893b2632ea6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_4ac682a5-c8f3-4f3c-98e9-615f6fb2b4d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_260714fc-d2e8-4992-aa0d-f893b2632ea6" xlink:to="loc_us-gaap_InterestRateSwapMember_4ac682a5-c8f3-4f3c-98e9-615f6fb2b4d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_bed7e46d-99dd-4738-80ae-131359d3bc45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_269de877-c939-4ec1-ab25-72a3a0e67c6f" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_bed7e46d-99dd-4738-80ae-131359d3bc45" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_bed7e46d-99dd-4738-80ae-131359d3bc45_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_bed7e46d-99dd-4738-80ae-131359d3bc45" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_bed7e46d-99dd-4738-80ae-131359d3bc45_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_e8a0be8a-e32c-4bb4-86ec-73a51cd73880" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_bed7e46d-99dd-4738-80ae-131359d3bc45" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_e8a0be8a-e32c-4bb4-86ec-73a51cd73880" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_51f1ac23-11ec-48e4-90f7-535d8421661c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_e8a0be8a-e32c-4bb4-86ec-73a51cd73880" xlink:to="loc_us-gaap_OtherAssetsMember_51f1ac23-11ec-48e4-90f7-535d8421661c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_3c08ac6e-31e5-46ac-aabd-658c1c655d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_3c08ac6e-31e5-46ac-aabd-658c1c655d6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MaximumIncreaseInBorrowingCapacity_e414de82-a6dd-45be-9545-ed36d8a6b4a1" xlink:href="kwr-20241231.xsd#kwr_MaximumIncreaseInBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_MaximumIncreaseInBorrowingCapacity_e414de82-a6dd-45be-9545-ed36d8a6b4a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_CreditFacilityAsPercentageOfConsolidatedEBITDA_7cfa3122-ffe2-419d-8def-2bf7b20d363c" xlink:href="kwr-20241231.xsd#kwr_CreditFacilityAsPercentageOfConsolidatedEBITDA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_CreditFacilityAsPercentageOfConsolidatedEBITDA_7cfa3122-ffe2-419d-8def-2bf7b20d363c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_25b71086-bf73-4857-b397-58c3f8aab92b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_25b71086-bf73-4857-b397-58c3f8aab92b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_InterestRateAdjustmentPercentage_9d3fe951-bf56-4cef-8e54-f738077d9407" xlink:href="kwr-20241231.xsd#kwr_InterestRateAdjustmentPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_InterestRateAdjustmentPercentage_9d3fe951-bf56-4cef-8e54-f738077d9407" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MaximumAmountOfDividendsAndShareRepurchasesUnderCovenant_75d92d46-272b-44b8-b192-6115139c646f" xlink:href="kwr-20241231.xsd#kwr_MaximumAmountOfDividendsAndShareRepurchasesUnderCovenant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_MaximumAmountOfDividendsAndShareRepurchasesUnderCovenant_75d92d46-272b-44b8-b192-6115139c646f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PercentageOfDividendsAndShareRepurchaseOfConsolidatedAdjustedEBITDA_163fafc6-85da-4706-90b4-e491bf9f549e" xlink:href="kwr-20241231.xsd#kwr_PercentageOfDividendsAndShareRepurchaseOfConsolidatedAdjustedEBITDA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_PercentageOfDividendsAndShareRepurchaseOfConsolidatedAdjustedEBITDA_163fafc6-85da-4706-90b4-e491bf9f549e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ConsolidatedNetLeverageRatio_264aff9b-2af4-43fa-a4a8-13411de9de2e" xlink:href="kwr-20241231.xsd#kwr_ConsolidatedNetLeverageRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_ConsolidatedNetLeverageRatio_264aff9b-2af4-43fa-a4a8-13411de9de2e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_InitialConsolidatedNetDebtToConsolidatedEbitdaRatio_1b13dcc0-92f7-499c-9a98-b4e19fef814c" xlink:href="kwr-20241231.xsd#kwr_InitialConsolidatedNetDebtToConsolidatedEbitdaRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_InitialConsolidatedNetDebtToConsolidatedEbitdaRatio_1b13dcc0-92f7-499c-9a98-b4e19fef814c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtPercentageBearingVariableInterestRate_bf08e374-ee73-4b47-8b1a-691d6622277c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtPercentageBearingVariableInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_LongTermDebtPercentageBearingVariableInterestRate_bf08e374-ee73-4b47-8b1a-691d6622277c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_608c0080-39e1-41f1-af56-47328c885bf0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_608c0080-39e1-41f1-af56-47328c885bf0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_0fd2b95b-9a6b-443a-a2af-d9145f057746" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_0fd2b95b-9a6b-443a-a2af-d9145f057746" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_083d0db5-f8c8-42dc-be51-f70cd07e36cc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_083d0db5-f8c8-42dc-be51-f70cd07e36cc" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_45c0f7c6-d386-4f39-8d1d-2d867eaf48e6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_45c0f7c6-d386-4f39-8d1d-2d867eaf48e6" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_bb34acce-1c41-47d8-9a34-7e6f4f908b63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeBasisSpreadOnVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DerivativeBasisSpreadOnVariableRate_bb34acce-1c41-47d8-9a34-7e6f4f908b63" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_3df01e17-7f19-417e-bd89-83e0dcb736f6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_3df01e17-7f19-417e-bd89-83e0dcb736f6" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_92696bfa-05f9-4c1e-af9c-85665e039431" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_92696bfa-05f9-4c1e-af9c-85665e039431" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtTerm_06e8f16f-915e-4262-84a4-0c277d9e0bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_LongTermDebtTerm_06e8f16f-915e-4262-84a4-0c277d9e0bf9" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsCurrentNet_f1d0a11c-bd2d-4283-ad30-411f474181bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsCurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_us-gaap_DeferredFinanceCostsCurrentNet_f1d0a11c-bd2d-4283-ad30-411f474181bb" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_Industrialdevelopmentrevenuebond_9eaac774-00bf-4cca-9b0a-310fc6ca64dd" xlink:href="kwr-20241231.xsd#kwr_Industrialdevelopmentrevenuebond"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_59c33a00-520f-448b-a671-340e906704bd" xlink:to="loc_kwr_Industrialdevelopmentrevenuebond_9eaac774-00bf-4cca-9b0a-310fc6ca64dd" xlink:type="arc" order="19"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostRetirementBenefitsChangeInBenefitObligationandPlanAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostRetirementBenefitsChangeInBenefitObligationandPlanAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostRetirementBenefitsChangeInBenefitObligationandPlanAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0991d70f-d23b-4137-99c5-a8a2d1785fa8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0991d70f-d23b-4137-99c5-a8a2d1785fa8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1a881a17-c105-452d-a68d-50e87a61d16f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0991d70f-d23b-4137-99c5-a8a2d1785fa8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1a881a17-c105-452d-a68d-50e87a61d16f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1a881a17-c105-452d-a68d-50e87a61d16f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1a881a17-c105-452d-a68d-50e87a61d16f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1a881a17-c105-452d-a68d-50e87a61d16f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_78912265-8b09-4d3f-bef3-e2d405c84b88" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1a881a17-c105-452d-a68d-50e87a61d16f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_78912265-8b09-4d3f-bef3-e2d405c84b88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_bc0e1207-8f32-48d2-a8fb-243a6ef16d36" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_78912265-8b09-4d3f-bef3-e2d405c84b88" xlink:to="loc_us-gaap_ForeignPlanMember_bc0e1207-8f32-48d2-a8fb-243a6ef16d36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_3a673d61-3bfd-4f47-8d73-e918b402cdb3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_78912265-8b09-4d3f-bef3-e2d405c84b88" xlink:to="loc_us-gaap_DomesticPlanMember_3a673d61-3bfd-4f47-8d73-e918b402cdb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_3fc24755-7ad9-428a-a6f5-7a63258eb6b6" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_3a673d61-3bfd-4f47-8d73-e918b402cdb3" xlink:to="loc_country_US_3fc24755-7ad9-428a-a6f5-7a63258eb6b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_67ae3715-3f53-4700-9ce1-19a383f39730" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0991d70f-d23b-4137-99c5-a8a2d1785fa8" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_67ae3715-3f53-4700-9ce1-19a383f39730" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_67ae3715-3f53-4700-9ce1-19a383f39730_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_67ae3715-3f53-4700-9ce1-19a383f39730" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_67ae3715-3f53-4700-9ce1-19a383f39730_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_a27c831d-db91-45f0-87f1-dbbf87d39948" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_67ae3715-3f53-4700-9ce1-19a383f39730" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_a27c831d-db91-45f0-87f1-dbbf87d39948" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_22935294-9e98-4114-ae33-afa60dca7cbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_a27c831d-db91-45f0-87f1-dbbf87d39948" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_22935294-9e98-4114-ae33-afa60dca7cbc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_49fa8c57-807d-4440-a4ca-c8468ca55ed5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_a27c831d-db91-45f0-87f1-dbbf87d39948" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_49fa8c57-807d-4440-a4ca-c8468ca55ed5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_927f8e9a-36de-4911-b77e-ae5b0fb6f3ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_927f8e9a-36de-4911-b77e-ae5b0fb6f3ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_1717e05a-0b32-479f-9fdf-d1311b4f3317" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_1717e05a-0b32-479f-9fdf-d1311b4f3317" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_27610a81-bd23-4827-aca4-ae1262e7f699" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_27610a81-bd23-4827-aca4-ae1262e7f699" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAmendments_f0e1cc54-d56b-4e37-9bb9-963f2916a1d1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAmendments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAmendments_f0e1cc54-d56b-4e37-9bb9-963f2916a1d1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCurtailments_a02b181e-4268-48d9-a46d-36060edc7bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanCurtailments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanCurtailments_a02b181e-4268-48d9-a46d-36060edc7bbd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_ff560d62-3094-4a26-b5de-20652f231195" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_ff560d62-3094-4a26-b5de-20652f231195" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DefinedBenefitPlanAdministrationExpensesBenefitObligations_bd9d7c81-4e05-42ea-a2b1-66851fdecaef" xlink:href="kwr-20241231.xsd#kwr_DefinedBenefitPlanAdministrationExpensesBenefitObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_kwr_DefinedBenefitPlanAdministrationExpensesBenefitObligations_bd9d7c81-4e05-42ea-a2b1-66851fdecaef" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_78e7f863-49d5-443c-949f-d0b5916a42c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_78e7f863-49d5-443c-949f-d0b5916a42c6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_6c5ce464-11fe-478b-aafe-2a420a7f7991" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_49224cb1-3d78-4765-8013-361328b5afa2" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_6c5ce464-11fe-478b-aafe-2a420a7f7991" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_0f1f7b86-e465-4e0c-b35e-7a57ef69b1ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_c19db2ce-dd29-4c8e-915e-718a7657fefc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_c19db2ce-dd29-4c8e-915e-718a7657fefc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_2c6ecec5-cd58-4184-bdf5-e80cce9bead8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_2c6ecec5-cd58-4184-bdf5-e80cce9bead8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_bf60b9c7-3e07-4441-b7c6-a2a295bee342" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_bf60b9c7-3e07-4441-b7c6-a2a295bee342" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_1ca5ae03-816e-4b36-bcd9-18ee31470c76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAdministrationExpenses_8359c6b2-31fd-4c03-ab7c-858de27a7d04" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAdministrationExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:to="loc_us-gaap_DefinedBenefitPlanAdministrationExpenses_8359c6b2-31fd-4c03-ab7c-858de27a7d04" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_3e9ef222-9767-4a82-b6e9-a50620650e76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_64d0a282-92d1-41ad-b04e-475e00da3138" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_3e9ef222-9767-4a82-b6e9-a50620650e76" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_e6b08e60-60e5-4e61-af67-4ad957bcae44" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_6cca7857-d0de-42fe-8488-b53109d373ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_6cca7857-d0de-42fe-8488-b53109d373ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetRelatedDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_a3064d76-1b52-4e1f-af9d-8577060bb4a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_a3064d76-1b52-4e1f-af9d-8577060bb4a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_5be3d9c4-f0ff-4800-86ac-3c119b55672d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_5be3d9c4-f0ff-4800-86ac-3c119b55672d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_d35952fa-7896-46f9-90ba-518aaf494ff5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_d35952fa-7896-46f9-90ba-518aaf494ff5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_c8b57bf3-7ac0-4cde-a0c1-1556e591518b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetRelatedDisclosuresAbstract_c0397cb5-5f85-4717-9dcf-5f98c5f8fc6d" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_c8b57bf3-7ac0-4cde-a0c1-1556e591518b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_2fc2a61e-6aab-41d0-888e-5f4741b1716f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_2fc2a61e-6aab-41d0-888e-5f4741b1716f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_768517f0-33f5-4af6-99ce-27d7de5b8fbb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_768517f0-33f5-4af6-99ce-27d7de5b8fbb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_ecb2750f-5b0c-4aad-9b96-144670dec1ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_ecb2750f-5b0c-4aad-9b96-144670dec1ad" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_CumulativeEmployerContributionsInExcessOfNetPeriodicBenefitCost_105f2595-cf91-432f-af01-14fdc3e48d7d" xlink:href="kwr-20241231.xsd#kwr_CumulativeEmployerContributionsInExcessOfNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a624c200-718c-4132-9fbb-02aa59abea3f" xlink:to="loc_kwr_CumulativeEmployerContributionsInExcessOfNetPeriodicBenefitCost_105f2595-cf91-432f-af01-14fdc3e48d7d" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_7f8d5232-6b1b-44cd-b58f-926cea44dab7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_7f8d5232-6b1b-44cd-b58f-926cea44dab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7f8d5232-6b1b-44cd-b58f-926cea44dab7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_7f8d5232-6b1b-44cd-b58f-926cea44dab7" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7f8d5232-6b1b-44cd-b58f-926cea44dab7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_877e63f1-a51f-4ded-93c3-211d344d09d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_7f8d5232-6b1b-44cd-b58f-926cea44dab7" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_877e63f1-a51f-4ded-93c3-211d344d09d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_1365ff5f-7e7e-4aa4-94b1-9b7d4a0d83f8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_877e63f1-a51f-4ded-93c3-211d344d09d7" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_1365ff5f-7e7e-4aa4-94b1-9b7d4a0d83f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_8606d79e-2523-4c16-b186-09851a135e86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_877e63f1-a51f-4ded-93c3-211d344d09d7" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_8606d79e-2523-4c16-b186-09851a135e86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_d3103bbf-23ff-4be0-93d3-4e1fcc6eb0e8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_877e63f1-a51f-4ded-93c3-211d344d09d7" xlink:to="loc_us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember_d3103bbf-23ff-4be0-93d3-4e1fcc6eb0e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_b5a52261-349e-42e0-9c0f-4fa36152cc4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_b5a52261-349e-42e0-9c0f-4fa36152cc4c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_b5a52261-349e-42e0-9c0f-4fa36152cc4c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_b5a52261-349e-42e0-9c0f-4fa36152cc4c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_b5a52261-349e-42e0-9c0f-4fa36152cc4c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e4b5530e-c401-4a4e-9f44-ae07a0ab8264" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_b5a52261-349e-42e0-9c0f-4fa36152cc4c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e4b5530e-c401-4a4e-9f44-ae07a0ab8264" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_2764bd29-2a2b-4d44-b4d1-df5430423ae5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e4b5530e-c401-4a4e-9f44-ae07a0ab8264" xlink:to="loc_us-gaap_DomesticPlanMember_2764bd29-2a2b-4d44-b4d1-df5430423ae5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_fab3a373-9830-43c2-a74b-01eab74141b8" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_2764bd29-2a2b-4d44-b4d1-df5430423ae5" xlink:to="loc_country_US_fab3a373-9830-43c2-a74b-01eab74141b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_84f96421-e74a-43b6-9d30-51a869f798a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e4b5530e-c401-4a4e-9f44-ae07a0ab8264" xlink:to="loc_us-gaap_ForeignPlanMember_84f96421-e74a-43b6-9d30-51a869f798a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d4e95be2-97d1-4225-b20f-3e967a33c7ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d4e95be2-97d1-4225-b20f-3e967a33c7ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_d4e95be2-97d1-4225-b20f-3e967a33c7ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d4e95be2-97d1-4225-b20f-3e967a33c7ce" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_d4e95be2-97d1-4225-b20f-3e967a33c7ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_321ce63b-948d-4601-ab8a-0b5960234543" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d4e95be2-97d1-4225-b20f-3e967a33c7ce" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_321ce63b-948d-4601-ab8a-0b5960234543" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_a0bc13c9-66ee-4845-9850-3e6f5167d432" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_321ce63b-948d-4601-ab8a-0b5960234543" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_a0bc13c9-66ee-4845-9850-3e6f5167d432" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedIncomeSecuritiesMember_e4e820e4-e400-4d65-9251-5c2f6a3a4a6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FixedIncomeSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_321ce63b-948d-4601-ab8a-0b5960234543" xlink:to="loc_us-gaap_FixedIncomeSecuritiesMember_e4e820e4-e400-4d65-9251-5c2f6a3a4a6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_c1ab1910-5bdb-480d-a448-32a78f9bf69a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_321ce63b-948d-4601-ab8a-0b5960234543" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_c1ab1910-5bdb-480d-a448-32a78f9bf69a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementAxis_188ed3f6-6ee7-4820-8979-aaae0a233516" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollectiveBargainingArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8ef20e71-fedc-4fc1-916f-92b234fa1708" xlink:to="loc_us-gaap_CollectiveBargainingArrangementAxis_188ed3f6-6ee7-4820-8979-aaae0a233516" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementDomain_188ed3f6-6ee7-4820-8979-aaae0a233516_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollectiveBargainingArrangementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollectiveBargainingArrangementAxis_188ed3f6-6ee7-4820-8979-aaae0a233516" xlink:to="loc_us-gaap_CollectiveBargainingArrangementDomain_188ed3f6-6ee7-4820-8979-aaae0a233516_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollectiveBargainingArrangementDomain_1d2d6cdc-0df4-4132-95f4-abea34b6fc52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollectiveBargainingArrangementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollectiveBargainingArrangementAxis_188ed3f6-6ee7-4820-8979-aaae0a233516" xlink:to="loc_us-gaap_CollectiveBargainingArrangementDomain_1d2d6cdc-0df4-4132-95f4-abea34b6fc52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_ClevelandBakersAndTeamstersPensionFundMember_9c3f640d-61eb-40c2-b052-34469c9205e6" xlink:href="kwr-20241231.xsd#kwr_ClevelandBakersAndTeamstersPensionFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollectiveBargainingArrangementDomain_1d2d6cdc-0df4-4132-95f4-abea34b6fc52" xlink:to="loc_kwr_ClevelandBakersAndTeamstersPensionFundMember_9c3f640d-61eb-40c2-b052-34469c9205e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_956552fb-6539-471a-a8cf-21f490864aa3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_956552fb-6539-471a-a8cf-21f490864aa3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryPercentage_aa370dcc-e38a-46ff-a715-06ef8eac8f9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsInvestmentWithinPlanAssetCategoryPercentage_aa370dcc-e38a-46ff-a715-06ef8eac8f9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DefinedBenefitPlanPlanAssetsLiquidatedAssets_c4b735a9-772c-4413-b58b-8bc90210edd8" xlink:href="kwr-20241231.xsd#kwr_DefinedBenefitPlanPlanAssetsLiquidatedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_kwr_DefinedBenefitPlanPlanAssetsLiquidatedAssets_c4b735a9-772c-4413-b58b-8bc90210edd8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_MultiemployerPlanPlanLiabilities_13cd8807-3730-4110-8bc7-2f69e9ebc737" xlink:href="kwr-20241231.xsd#kwr_MultiemployerPlanPlanLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_kwr_MultiemployerPlanPlanLiabilities_13cd8807-3730-4110-8bc7-2f69e9ebc737" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MultiemployerPlanPensionSignificantPlanAsset_8eed9543-942c-4c4a-9ed0-6be70aa7df99" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MultiemployerPlanPensionSignificantPlanAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_MultiemployerPlanPensionSignificantPlanAsset_8eed9543-942c-4c4a-9ed0-6be70aa7df99" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MultiemployerPlanPensionInsignificantPlanContribution_880ed92f-3b4b-4dd6-bb76-b5848d287315" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MultiemployerPlanPensionInsignificantPlanContribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_MultiemployerPlanPensionInsignificantPlanContribution_880ed92f-3b4b-4dd6-bb76-b5848d287315" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_5418f969-c29c-4b5f-8c85-2bebb1f43ecf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_5418f969-c29c-4b5f-8c85-2bebb1f43ecf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_b302d18e-8d46-4e40-8048-cb7608c7ed6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_b302d18e-8d46-4e40-8048-cb7608c7ed6c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_4453efe6-4ab7-4171-ad3a-c882d53e4f65" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a2b64484-4088-49c4-8c8c-840d992e8c53" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_4453efe6-4ab7-4171-ad3a-c882d53e4f65" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsInformationAboutAccumulatedandProjectedBenefitObligationsInExcessofPlanAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsInformationAboutAccumulatedandProjectedBenefitObligationsInExcessofPlanAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsInformationAboutAccumulatedandProjectedBenefitObligationsInExcessofPlanAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3ed8424d-9c8c-442a-81e7-7f80c7e4fd99" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0ec22c22-f4f3-4d39-ae09-d3e45b4388c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3ed8424d-9c8c-442a-81e7-7f80c7e4fd99" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0ec22c22-f4f3-4d39-ae09-d3e45b4388c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0ec22c22-f4f3-4d39-ae09-d3e45b4388c3" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_6baa2a15-4370-4fcf-8377-a8ff72c2138e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_89dc2cea-7d53-4ef1-8a1f-23e470dcb5dd" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_6baa2a15-4370-4fcf-8377-a8ff72c2138e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_4be224ee-b3a7-498d-8875-31415f1f9d1d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6baa2a15-4370-4fcf-8377-a8ff72c2138e" xlink:to="loc_us-gaap_ForeignPlanMember_4be224ee-b3a7-498d-8875-31415f1f9d1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_cfbae23e-0bef-40ea-8efc-98e4fc7279bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6baa2a15-4370-4fcf-8377-a8ff72c2138e" xlink:to="loc_us-gaap_DomesticPlanMember_cfbae23e-0bef-40ea-8efc-98e4fc7279bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_01572b47-512a-4d5e-8b74-95ca84da60ba" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_cfbae23e-0bef-40ea-8efc-98e4fc7279bb" xlink:to="loc_country_US_01572b47-512a-4d5e-8b74-95ca84da60ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_c24242ad-6d96-4725-9f67-fc4d583417ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0ec22c22-f4f3-4d39-ae09-d3e45b4388c3" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_c24242ad-6d96-4725-9f67-fc4d583417ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_c24242ad-6d96-4725-9f67-fc4d583417ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_c24242ad-6d96-4725-9f67-fc4d583417ce" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_c24242ad-6d96-4725-9f67-fc4d583417ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_8ec09ef3-f828-4632-892e-9135374f5478" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_c24242ad-6d96-4725-9f67-fc4d583417ce" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_8ec09ef3-f828-4632-892e-9135374f5478" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_41f465c4-2367-4018-9abc-fdc01ef909d4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_8ec09ef3-f828-4632-892e-9135374f5478" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_41f465c4-2367-4018-9abc-fdc01ef909d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_c446ee39-6227-4a06-b0b8-fcfc668053ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_8ec09ef3-f828-4632-892e-9135374f5478" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_c446ee39-6227-4a06-b0b8-fcfc668053ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_d2b99bc3-4e29-4cc3-aae9-889e44b5f6b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3ed8424d-9c8c-442a-81e7-7f80c7e4fd99" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_d2b99bc3-4e29-4cc3-aae9-889e44b5f6b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_2779f3e5-9de6-4e78-a150-4bf3cc2665ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_d2b99bc3-4e29-4cc3-aae9-889e44b5f6b3" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_2779f3e5-9de6-4e78-a150-4bf3cc2665ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_1170ad49-4e8d-4d05-b31f-3b940ea4cc77" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_d2b99bc3-4e29-4cc3-aae9-889e44b5f6b3" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_1170ad49-4e8d-4d05-b31f-3b940ea4cc77" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_2357333a-91c1-4aa8-b83c-6a89eec03b59" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3ed8424d-9c8c-442a-81e7-7f80c7e4fd99" xlink:to="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_2357333a-91c1-4aa8-b83c-6a89eec03b59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_88c505da-79d0-44bc-ac88-d854a749b7de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_2357333a-91c1-4aa8-b83c-6a89eec03b59" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_88c505da-79d0-44bc-ac88-d854a749b7de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_79bf5b68-af63-4a42-850a-b2aa76a47791" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_2357333a-91c1-4aa8-b83c-6a89eec03b59" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_79bf5b68-af63-4a42-850a-b2aa76a47791" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsNetPeriodicBenefitCostandChangesinOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsNetPeriodicBenefitCostandChangesinOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsNetPeriodicBenefitCostandChangesinOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8a034f70-4fb4-44f3-a820-bb23972ed7ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_220e9ad7-d1cb-4b99-9e40-3fd6784e91c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8a034f70-4fb4-44f3-a820-bb23972ed7ba" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_220e9ad7-d1cb-4b99-9e40-3fd6784e91c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_62958300-d3a9-4475-868c-8b121a4e911d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_220e9ad7-d1cb-4b99-9e40-3fd6784e91c3" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_62958300-d3a9-4475-868c-8b121a4e911d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_62958300-d3a9-4475-868c-8b121a4e911d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_62958300-d3a9-4475-868c-8b121a4e911d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_62958300-d3a9-4475-868c-8b121a4e911d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_2600b9e3-1cba-4e15-b96c-2ebb9ae61585" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_62958300-d3a9-4475-868c-8b121a4e911d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_2600b9e3-1cba-4e15-b96c-2ebb9ae61585" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_2e63471c-88f1-4baa-8baf-763d837ce329" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_2600b9e3-1cba-4e15-b96c-2ebb9ae61585" xlink:to="loc_us-gaap_ForeignPlanMember_2e63471c-88f1-4baa-8baf-763d837ce329" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_b534ab14-7864-4197-88d0-716d7f892558" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_2600b9e3-1cba-4e15-b96c-2ebb9ae61585" xlink:to="loc_us-gaap_DomesticPlanMember_b534ab14-7864-4197-88d0-716d7f892558" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_dd726fab-04bc-4f69-805d-880bec73ed2c" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_b534ab14-7864-4197-88d0-716d7f892558" xlink:to="loc_country_US_dd726fab-04bc-4f69-805d-880bec73ed2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_bc04a671-9d41-4bd4-b65e-cf7810179f37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_220e9ad7-d1cb-4b99-9e40-3fd6784e91c3" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_bc04a671-9d41-4bd4-b65e-cf7810179f37" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_bc04a671-9d41-4bd4-b65e-cf7810179f37_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_bc04a671-9d41-4bd4-b65e-cf7810179f37" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_bc04a671-9d41-4bd4-b65e-cf7810179f37_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1297834e-6e3b-41eb-912f-7dd18b7ad635" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_bc04a671-9d41-4bd4-b65e-cf7810179f37" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1297834e-6e3b-41eb-912f-7dd18b7ad635" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_d5bbf2ba-4a78-4865-a42b-a075b00e9211" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1297834e-6e3b-41eb-912f-7dd18b7ad635" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_d5bbf2ba-4a78-4865-a42b-a075b00e9211" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_ad683984-a1ac-4838-b977-60bb7617df6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1297834e-6e3b-41eb-912f-7dd18b7ad635" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_ad683984-a1ac-4838-b977-60bb7617df6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8a034f70-4fb4-44f3-a820-bb23972ed7ba" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_64b05f29-0e10-48e9-b982-bfcdf9054389" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_64b05f29-0e10-48e9-b982-bfcdf9054389" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_6a66aa70-970f-4aee-b6ed-41b4d8772b7f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_6a66aa70-970f-4aee-b6ed-41b4d8772b7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_e6a0db87-b762-42de-9147-a9414d9dc1aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_e6a0db87-b762-42de-9147-a9414d9dc1aa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_b52bb696-550f-48a6-a1b5-22f13afe2b5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1_b52bb696-550f-48a6-a1b5-22f13afe2b5d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_e82c576b-0fcb-4094-a002-8dba41614619" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments_e82c576b-0fcb-4094-a002-8dba41614619" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9313465d-95ff-4e0b-8886-a509f72941f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9313465d-95ff-4e0b-8886-a509f72941f4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_e5a18668-2033-4d93-8b5c-16369c3d1dd5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_e5a18668-2033-4d93-8b5c-16369c3d1dd5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_ca024885-53e2-4453-9f62-7e479f02a302" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_f09c654b-2045-4e06-94cb-7bb3d4895204" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_ca024885-53e2-4453-9f62-7e479f02a302" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8a034f70-4fb4-44f3-a820-bb23972ed7ba" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_1650fa6a-7fe9-4aed-abfe-875b1472e9e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax_1650fa6a-7fe9-4aed-abfe-875b1472e9e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_Othercomprehensiveincomelossplansettlement_6564ec39-c219-45a0-8727-c30b61d265a9" xlink:href="kwr-20241231.xsd#kwr_Othercomprehensiveincomelossplansettlement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_kwr_Othercomprehensiveincomelossplansettlement_6564ec39-c219-45a0-8727-c30b61d265a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_c3c68d34-1924-4e46-84f9-7421cb47f4fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax_c3c68d34-1924-4e46-84f9-7421cb47f4fe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax_497dee4c-8d72-40a4-9aed-b13c38b9107b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostCreditArisingDuringPeriodBeforeTax_497dee4c-8d72-40a4-9aed-b13c38b9107b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DefinedBenefitPlanAmortizationOfGainsLossesWithSettlementLoss_7ef6e075-0026-4b10-ac09-36bdcd636bd5" xlink:href="kwr-20241231.xsd#kwr_DefinedBenefitPlanAmortizationOfGainsLossesWithSettlementLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_kwr_DefinedBenefitPlanAmortizationOfGainsLossesWithSettlementLoss_7ef6e075-0026-4b10-ac09-36bdcd636bd5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_Othercomprehensiveincomelossplancurtailments_fadbe667-076c-446c-920a-87507afb20aa" xlink:href="kwr-20241231.xsd#kwr_Othercomprehensiveincomelossplancurtailments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_kwr_Othercomprehensiveincomelossplancurtailments_fadbe667-076c-446c-920a-87507afb20aa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DefinedBenefitPlanForeignCurrencyExchangeRateChangesOtherComprehensiveIncomeLoss_0428bc76-58b7-41d7-b826-e6f1812d3f30" xlink:href="kwr-20241231.xsd#kwr_DefinedBenefitPlanForeignCurrencyExchangeRateChangesOtherComprehensiveIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_kwr_DefinedBenefitPlanForeignCurrencyExchangeRateChangesOtherComprehensiveIncomeLoss_0428bc76-58b7-41d7-b826-e6f1812d3f30" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax_94322ae8-a338-484d-b4a6-db71786c8316" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_b5308de5-3ae9-410a-aee1-5812a804794b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansBeforeTax_94322ae8-a338-484d-b4a6-db71786c8316" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_TotalRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveLossOrIncome_6ebb3e02-f82a-4f40-94b9-00841c6f99de" xlink:href="kwr-20241231.xsd#kwr_TotalRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveLossOrIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8a034f70-4fb4-44f3-a820-bb23972ed7ba" xlink:to="loc_kwr_TotalRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveLossOrIncome_6ebb3e02-f82a-4f40-94b9-00841c6f99de" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsAssumptionsUsedinDeterminingBenefitObligationsandNetPeriodicPensionCostsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsAssumptionsUsedinDeterminingBenefitObligationsandNetPeriodicPensionCostsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsAssumptionsUsedinDeterminingBenefitObligationsandNetPeriodicPensionCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_bd51b8aa-459e-4ada-bf3c-6cd2960d90a3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_f7b8a122-0e9f-4b08-af73-26865b34062a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_bd51b8aa-459e-4ada-bf3c-6cd2960d90a3" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_f7b8a122-0e9f-4b08-af73-26865b34062a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_8eff1480-d9fb-44a8-baa4-3d56c1913e11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_f7b8a122-0e9f-4b08-af73-26865b34062a" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_8eff1480-d9fb-44a8-baa4-3d56c1913e11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_8eff1480-d9fb-44a8-baa4-3d56c1913e11_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_8eff1480-d9fb-44a8-baa4-3d56c1913e11" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_8eff1480-d9fb-44a8-baa4-3d56c1913e11_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_068afa0e-ca55-45dc-96f7-fcd5e2fa3c20" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_8eff1480-d9fb-44a8-baa4-3d56c1913e11" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_068afa0e-ca55-45dc-96f7-fcd5e2fa3c20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_6f8fa9f8-990d-46f8-b0bd-18c15b53144f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_068afa0e-ca55-45dc-96f7-fcd5e2fa3c20" xlink:to="loc_us-gaap_DomesticPlanMember_6f8fa9f8-990d-46f8-b0bd-18c15b53144f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_a89edca5-3ad1-4fd8-9c91-158368bbb998" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_6f8fa9f8-990d-46f8-b0bd-18c15b53144f" xlink:to="loc_country_US_a89edca5-3ad1-4fd8-9c91-158368bbb998" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_437349d5-f2b7-4435-8c41-5ac1dd275e70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_068afa0e-ca55-45dc-96f7-fcd5e2fa3c20" xlink:to="loc_us-gaap_ForeignPlanMember_437349d5-f2b7-4435-8c41-5ac1dd275e70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_56bdd072-44f9-4b05-8297-9866e8ef85fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_f7b8a122-0e9f-4b08-af73-26865b34062a" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_56bdd072-44f9-4b05-8297-9866e8ef85fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_56bdd072-44f9-4b05-8297-9866e8ef85fb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_56bdd072-44f9-4b05-8297-9866e8ef85fb" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_56bdd072-44f9-4b05-8297-9866e8ef85fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_8771bf7d-ac64-4e06-a9af-e21a5237aeb9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_56bdd072-44f9-4b05-8297-9866e8ef85fb" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_8771bf7d-ac64-4e06-a9af-e21a5237aeb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_ab0578bb-9d1e-4aa4-8dd9-ea17f6811b33" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_8771bf7d-ac64-4e06-a9af-e21a5237aeb9" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_ab0578bb-9d1e-4aa4-8dd9-ea17f6811b33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_d86a6aba-ff87-4028-8e67-194ce019e868" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_8771bf7d-ac64-4e06-a9af-e21a5237aeb9" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_d86a6aba-ff87-4028-8e67-194ce019e868" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_6942bb62-5de9-4e2e-8f9a-67451353aa9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_bd51b8aa-459e-4ada-bf3c-6cd2960d90a3" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_6942bb62-5de9-4e2e-8f9a-67451353aa9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_83d2ea71-fece-40ca-a049-7a506eb42e20" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_6942bb62-5de9-4e2e-8f9a-67451353aa9e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_83d2ea71-fece-40ca-a049-7a506eb42e20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_4de8738d-80fc-4ec4-a86a-4d98f056ea6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract_6942bb62-5de9-4e2e-8f9a-67451353aa9e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease_4de8738d-80fc-4ec4-a86a-4d98f056ea6c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e9332645-9527-4d97-b7c2-6ca50640eb52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_bd51b8aa-459e-4ada-bf3c-6cd2960d90a3" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e9332645-9527-4d97-b7c2-6ca50640eb52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_c4af3d33-2530-4814-99e8-8bd7459874fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e9332645-9527-4d97-b7c2-6ca50640eb52" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_c4af3d33-2530-4814-99e8-8bd7459874fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_94647768-a2ab-410f-868f-c7a180bbdfcd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e9332645-9527-4d97-b7c2-6ca50640eb52" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_94647768-a2ab-410f-868f-c7a180bbdfcd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_f979207f-4048-42ae-8533-abbdd852abec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract_e9332645-9527-4d97-b7c2-6ca50640eb52" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_f979207f-4048-42ae-8533-abbdd852abec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_405e1f83-310e-430d-8e08-68c389427f26" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_bd51b8aa-459e-4ada-bf3c-6cd2960d90a3" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_405e1f83-310e-430d-8e08-68c389427f26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_f4a8a10e-4532-4b39-8c95-046b4937855e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_405e1f83-310e-430d-8e08-68c389427f26" xlink:to="loc_us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_f4a8a10e-4532-4b39-8c95-046b4937855e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_32714b22-01a5-4143-b475-3ca8f212114b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_405e1f83-310e-430d-8e08-68c389427f26" xlink:to="loc_us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1_32714b22-01a5-4143-b475-3ca8f212114b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate_33970396-8601-4aea-aca9-d36c204fee8e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract_405e1f83-310e-430d-8e08-68c389427f26" xlink:to="loc_us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate_33970396-8601-4aea-aca9-d36c204fee8e" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsAssetAllocationsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsAssetAllocationsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsAssetAllocationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_e7555a9c-2142-42e9-9be8-c8bdeda1330c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_26a0827c-1db7-4984-9fde-b859d140403c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_e7555a9c-2142-42e9-9be8-c8bdeda1330c" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_26a0827c-1db7-4984-9fde-b859d140403c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_5d1f8814-43b1-472b-99cc-5aae23bbd526" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_26a0827c-1db7-4984-9fde-b859d140403c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_5d1f8814-43b1-472b-99cc-5aae23bbd526" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_5d1f8814-43b1-472b-99cc-5aae23bbd526_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_5d1f8814-43b1-472b-99cc-5aae23bbd526" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_5d1f8814-43b1-472b-99cc-5aae23bbd526_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_285d747f-ac66-4e70-96b8-5bf75374b2d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_5d1f8814-43b1-472b-99cc-5aae23bbd526" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_285d747f-ac66-4e70-96b8-5bf75374b2d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_fa950709-6d33-491a-bc33-d646e97aaf06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_285d747f-ac66-4e70-96b8-5bf75374b2d3" xlink:to="loc_us-gaap_DomesticPlanMember_fa950709-6d33-491a-bc33-d646e97aaf06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_f505b076-5b51-4fea-a06e-98c119a7807f" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_fa950709-6d33-491a-bc33-d646e97aaf06" xlink:to="loc_country_US_f505b076-5b51-4fea-a06e-98c119a7807f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_7fc24d69-2ea2-4d3c-ba0f-fb4c0f1caf9a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_285d747f-ac66-4e70-96b8-5bf75374b2d3" xlink:to="loc_us-gaap_ForeignPlanMember_7fc24d69-2ea2-4d3c-ba0f-fb4c0f1caf9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_6b83f7bc-8e7e-40dd-803e-b987f675a4e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_26a0827c-1db7-4984-9fde-b859d140403c" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_6b83f7bc-8e7e-40dd-803e-b987f675a4e7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_6b83f7bc-8e7e-40dd-803e-b987f675a4e7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_6b83f7bc-8e7e-40dd-803e-b987f675a4e7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_6b83f7bc-8e7e-40dd-803e-b987f675a4e7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_f6b9e1c9-f0f8-4473-9518-378cbc696cc2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_6b83f7bc-8e7e-40dd-803e-b987f675a4e7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_f6b9e1c9-f0f8-4473-9518-378cbc696cc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_6f28611e-1ba6-48a3-914d-cb3b042f3ef9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f6b9e1c9-f0f8-4473-9518-378cbc696cc2" xlink:to="loc_us-gaap_EquitySecuritiesMember_6f28611e-1ba6-48a3-914d-cb3b042f3ef9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesMember_89c32960-cfdc-49d2-95a9-2434695bdc39" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f6b9e1c9-f0f8-4473-9518-378cbc696cc2" xlink:to="loc_us-gaap_DebtSecuritiesMember_89c32960-cfdc-49d2-95a9-2434695bdc39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_OtherMember_eb7cdb4c-fc90-4ba3-ae2d-82a724e4113f" xlink:href="kwr-20241231.xsd#kwr_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f6b9e1c9-f0f8-4473-9518-378cbc696cc2" xlink:to="loc_kwr_OtherMember_eb7cdb4c-fc90-4ba3-ae2d-82a724e4113f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_26a0827c-1db7-4984-9fde-b859d140403c" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_c3db97dd-8159-479b-ad65-a7035767d906" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2c50f9a5-36c8-4dd6-aa16-9080a8dc47a4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_c3db97dd-8159-479b-ad65-a7035767d906" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_570b9ec7-d12c-42e0-8a9b-368c4a13a673" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_c3db97dd-8159-479b-ad65-a7035767d906" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_570b9ec7-d12c-42e0-8a9b-368c4a13a673" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_1919eb80-d19d-4b2e-8efb-f35d733dfa49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_e7555a9c-2142-42e9-9be8-c8bdeda1330c" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_1919eb80-d19d-4b2e-8efb-f35d733dfa49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_9c0de750-f47c-4f1c-92dc-25ec59bae448" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_e7555a9c-2142-42e9-9be8-c8bdeda1330c" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_9c0de750-f47c-4f1c-92dc-25ec59bae448" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsFairValueHierarchyAssetsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsFairValueHierarchyAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsFairValueHierarchyAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ce6fc791-5426-476a-9bf9-9f95c2d95041" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ce6fc791-5426-476a-9bf9-9f95c2d95041" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_393235c1-af68-40db-82ce-8a03dd1f028f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_393235c1-af68-40db-82ce-8a03dd1f028f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_393235c1-af68-40db-82ce-8a03dd1f028f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_393235c1-af68-40db-82ce-8a03dd1f028f" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_393235c1-af68-40db-82ce-8a03dd1f028f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_a57ae9fe-9801-484a-8d6f-c4e85512cf24" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_393235c1-af68-40db-82ce-8a03dd1f028f" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_a57ae9fe-9801-484a-8d6f-c4e85512cf24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_e0811a85-3f1d-49a5-992d-ff18ffb6ce76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_a57ae9fe-9801-484a-8d6f-c4e85512cf24" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_e0811a85-3f1d-49a5-992d-ff18ffb6ce76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_54b024ec-9ce1-48e8-9b87-5408aed94cca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_92499ba8-f8d2-4b0d-bd8b-7b7d2128e5a8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_54b024ec-9ce1-48e8-9b87-5408aed94cca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_cd149e1d-0f80-4a01-88d7-0d633f0fbc63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_54b024ec-9ce1-48e8-9b87-5408aed94cca" xlink:to="loc_us-gaap_DomesticPlanMember_cd149e1d-0f80-4a01-88d7-0d633f0fbc63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_7ff2652d-790c-4083-89b7-b1c20c0c2aa4" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_cd149e1d-0f80-4a01-88d7-0d633f0fbc63" xlink:to="loc_country_US_7ff2652d-790c-4083-89b7-b1c20c0c2aa4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_2923e3bf-a053-41ca-afb3-6b724f4cdfea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_54b024ec-9ce1-48e8-9b87-5408aed94cca" xlink:to="loc_us-gaap_ForeignPlanMember_2923e3bf-a053-41ca-afb3-6b724f4cdfea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7901d99a-5ac9-4530-9499-38f491dbad54" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7901d99a-5ac9-4530-9499-38f491dbad54" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_7901d99a-5ac9-4530-9499-38f491dbad54_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7901d99a-5ac9-4530-9499-38f491dbad54" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_7901d99a-5ac9-4530-9499-38f491dbad54_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7901d99a-5ac9-4530-9499-38f491dbad54" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PooledSeparateAccountsMember_37c80b62-c426-4699-b9d4-8ee99b90d929" xlink:href="kwr-20241231.xsd#kwr_PooledSeparateAccountsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_kwr_PooledSeparateAccountsMember_37c80b62-c426-4699-b9d4-8ee99b90d929" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_RealEstateFundMember_99f7885e-9ba1-4007-ac9b-a4efd1652f70" xlink:href="kwr-20241231.xsd#kwr_RealEstateFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_kwr_RealEstateFundMember_99f7885e-9ba1-4007-ac9b-a4efd1652f70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_6ee8ef55-5b87-49ac-aab4-ec27b2e6a300" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_6ee8ef55-5b87-49ac-aab4-ec27b2e6a300" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_InsuranceContractMember_b3e23859-13e8-4942-9bd7-11b3c91c53df" xlink:href="kwr-20241231.xsd#kwr_InsuranceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_kwr_InsuranceContractMember_b3e23859-13e8-4942-9bd7-11b3c91c53df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EquityFundsDiversifiedMember_e8719662-82c1-437e-b570-fa8c5c49b649" xlink:href="kwr-20241231.xsd#kwr_EquityFundsDiversifiedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_kwr_EquityFundsDiversifiedMember_e8719662-82c1-437e-b570-fa8c5c49b649" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedIncomeFundsMember_4fa249d4-290f-4745-9cad-6784b1be977f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FixedIncomeFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_us-gaap_FixedIncomeFundsMember_4fa249d4-290f-4745-9cad-6784b1be977f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_CommingledFundsMember_6ffd0f10-a57e-4baf-9f2d-9a4d33b192a9" xlink:href="kwr-20241231.xsd#kwr_CommingledFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_d6265dc5-7808-4f9e-bdcc-4b2d3cc5c68d" xlink:to="loc_kwr_CommingledFundsMember_6ffd0f10-a57e-4baf-9f2d-9a4d33b192a9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6c4f9346-55f6-40af-97c2-560f9ba9936d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_635c8f64-12dc-49e4-a57a-685835a051fd" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6c4f9346-55f6-40af-97c2-560f9ba9936d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6c4f9346-55f6-40af-97c2-560f9ba9936d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6c4f9346-55f6-40af-97c2-560f9ba9936d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6c4f9346-55f6-40af-97c2-560f9ba9936d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_642d8fe7-fd64-47e2-95ba-60437b8ede32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6c4f9346-55f6-40af-97c2-560f9ba9936d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_642d8fe7-fd64-47e2-95ba-60437b8ede32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel12And3Member_592f63ce-32e3-46c3-a299-35e0015522a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel12And3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_642d8fe7-fd64-47e2-95ba-60437b8ede32" xlink:to="loc_us-gaap_FairValueInputsLevel12And3Member_592f63ce-32e3-46c3-a299-35e0015522a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_cef6213b-ec7a-45db-9557-383e3184e0a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueInputsLevel12And3Member_592f63ce-32e3-46c3-a299-35e0015522a7" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_cef6213b-ec7a-45db-9557-383e3184e0a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_19a49b32-473c-4b9b-8fac-d3b44a252c86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueInputsLevel12And3Member_592f63ce-32e3-46c3-a299-35e0015522a7" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_19a49b32-473c-4b9b-8fac-d3b44a252c86" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_18f78977-829a-4499-9bed-21ab84801e97" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueInputsLevel12And3Member_592f63ce-32e3-46c3-a299-35e0015522a7" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_18f78977-829a-4499-9bed-21ab84801e97" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_726ece1e-8945-4fbd-9962-b78f73f43425" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_642d8fe7-fd64-47e2-95ba-60437b8ede32" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_726ece1e-8945-4fbd-9962-b78f73f43425" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_33edebd2-ea5b-444f-acbb-41abe57868f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_ce6fc791-5426-476a-9bf9-9f95c2d95041" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_33edebd2-ea5b-444f-acbb-41abe57868f5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsLevel3AssetRollforwardDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsLevel3AssetRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsLevel3AssetRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_590813ac-980d-4b72-93ed-e0f8200acf67" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1c7f9cd9-824b-4ba4-8ff6-e5f7b899d2dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_590813ac-980d-4b72-93ed-e0f8200acf67" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1c7f9cd9-824b-4ba4-8ff6-e5f7b899d2dc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1c7f9cd9-824b-4ba4-8ff6-e5f7b899d2dc" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_a3cd2a09-24a7-44e7-ac60-5c6281ed2163" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_2db10c8d-4457-4f1f-b1b8-8ff52ea0c468" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_a3cd2a09-24a7-44e7-ac60-5c6281ed2163" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_InsuranceContractMember_af81a8af-ae35-4ba2-93e7-e74f09b09d5c" xlink:href="kwr-20241231.xsd#kwr_InsuranceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_a3cd2a09-24a7-44e7-ac60-5c6281ed2163" xlink:to="loc_kwr_InsuranceContractMember_af81a8af-ae35-4ba2-93e7-e74f09b09d5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_RealEstateFundMember_197ac787-951d-4bd9-b7f7-9632ac222ce4" xlink:href="kwr-20241231.xsd#kwr_RealEstateFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_a3cd2a09-24a7-44e7-ac60-5c6281ed2163" xlink:to="loc_kwr_RealEstateFundMember_197ac787-951d-4bd9-b7f7-9632ac222ce4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b6598cf5-5971-4e7b-b00c-0fd6d881722c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_1c7f9cd9-824b-4ba4-8ff6-e5f7b899d2dc" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b6598cf5-5971-4e7b-b00c-0fd6d881722c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b6598cf5-5971-4e7b-b00c-0fd6d881722c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b6598cf5-5971-4e7b-b00c-0fd6d881722c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b6598cf5-5971-4e7b-b00c-0fd6d881722c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f396dc87-11e5-49a6-b691-75c3c2aa20f6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b6598cf5-5971-4e7b-b00c-0fd6d881722c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f396dc87-11e5-49a6-b691-75c3c2aa20f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_bde2e3bf-1bd5-42a1-a06d-fdcf4a4861ab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f396dc87-11e5-49a6-b691-75c3c2aa20f6" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_bde2e3bf-1bd5-42a1-a06d-fdcf4a4861ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_590813ac-980d-4b72-93ed-e0f8200acf67" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_f27bf5f7-8674-4a70-80e4-472e931bfc37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_f27bf5f7-8674-4a70-80e4-472e931bfc37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_DefinedBenefitPlanPlanAssetsLevel3ReconciliationAdjustmentsForPurchase_2613bd18-b40f-485c-801b-b149ae328f7e" xlink:href="kwr-20241231.xsd#kwr_DefinedBenefitPlanPlanAssetsLevel3ReconciliationAdjustmentsForPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:to="loc_kwr_DefinedBenefitPlanPlanAssetsLevel3ReconciliationAdjustmentsForPurchase_2613bd18-b40f-485c-801b-b149ae328f7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld_088f0294-9f1f-4643-87c5-facfb0dcd094" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld_088f0294-9f1f-4643-87c5-facfb0dcd094" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_3102e42c-5872-4a7e-9bec-6897a3405770" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a5632747-a43d-470b-a20a-bf58b30bcc3c" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_3102e42c-5872-4a7e-9bec-6897a3405770" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_fb583091-1632-4e19-af69-b1b3417a41eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsCashFlowDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#PensionandOtherPostretirementBenefitsCashFlowDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/PensionandOtherPostretirementBenefitsCashFlowDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_406fc6f8-bdbc-48dd-9318-cd94fb7d382e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_406fc6f8-bdbc-48dd-9318-cd94fb7d382e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_be4b77ba-00c4-4e99-a14a-e58d04a3ba25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_406fc6f8-bdbc-48dd-9318-cd94fb7d382e" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_be4b77ba-00c4-4e99-a14a-e58d04a3ba25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_be4b77ba-00c4-4e99-a14a-e58d04a3ba25_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_be4b77ba-00c4-4e99-a14a-e58d04a3ba25" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_be4b77ba-00c4-4e99-a14a-e58d04a3ba25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_72a48178-676a-41d4-98de-be18c6055c25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_be4b77ba-00c4-4e99-a14a-e58d04a3ba25" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_72a48178-676a-41d4-98de-be18c6055c25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_41340b70-f078-45e1-bcb5-adae6eca591a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_72a48178-676a-41d4-98de-be18c6055c25" xlink:to="loc_us-gaap_ForeignPlanMember_41340b70-f078-45e1-bcb5-adae6eca591a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_3f76031b-45b6-4b27-833e-050fd5b4992d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_72a48178-676a-41d4-98de-be18c6055c25" xlink:to="loc_us-gaap_DomesticPlanMember_3f76031b-45b6-4b27-833e-050fd5b4992d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_5381db47-67b5-4466-9fdd-5549916d60cc" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_3f76031b-45b6-4b27-833e-050fd5b4992d" xlink:to="loc_country_US_5381db47-67b5-4466-9fdd-5549916d60cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_d8cbca28-3da0-4112-9347-1d268fcf75f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_406fc6f8-bdbc-48dd-9318-cd94fb7d382e" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_d8cbca28-3da0-4112-9347-1d268fcf75f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d8cbca28-3da0-4112-9347-1d268fcf75f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d8cbca28-3da0-4112-9347-1d268fcf75f9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d8cbca28-3da0-4112-9347-1d268fcf75f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_933d0bdb-56c2-4401-be70-8d7449df96cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d8cbca28-3da0-4112-9347-1d268fcf75f9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_933d0bdb-56c2-4401-be70-8d7449df96cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_4865fbee-ac9b-40cf-9688-2ab027102584" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_933d0bdb-56c2-4401-be70-8d7449df96cf" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_4865fbee-ac9b-40cf-9688-2ab027102584" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_75c481bd-9d63-482e-8c0a-d799ae002376" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_933d0bdb-56c2-4401-be70-8d7449df96cf" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_75c481bd-9d63-482e-8c0a-d799ae002376" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_0fd14ea5-6cb5-42bf-a018-ffbaf9e74c35" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_0fd14ea5-6cb5-42bf-a018-ffbaf9e74c35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_1e9ae4b5-f408-433c-a258-a4393eaa3baa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_1e9ae4b5-f408-433c-a258-a4393eaa3baa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_3ade8eed-8770-401c-9552-d718daf54174" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_3ade8eed-8770-401c-9552-d718daf54174" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_8721d8fb-2d5b-42be-bc04-b20a52115433" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_8721d8fb-2d5b-42be-bc04-b20a52115433" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_bf5ed307-a6eb-4a7e-a6a9-8bffba8b142a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_bf5ed307-a6eb-4a7e-a6a9-8bffba8b142a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_8db3a16d-bac5-4b18-b667-ad8dceb2b306" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c2befe92-8f67-4bce-84d9-6ffcb301a45e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_8db3a16d-bac5-4b18-b667-ad8dceb2b306" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/AccumulatedOtherComprehensiveLossAOCIReclassificationsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#AccumulatedOtherComprehensiveLossAOCIReclassificationsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/AccumulatedOtherComprehensiveLossAOCIReclassificationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_7179b770-3d8a-45fa-a572-3c9d03cb40b5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_8dbb730e-49b8-4f7d-a2e7-63e8e8f58eb9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_7179b770-3d8a-45fa-a572-3c9d03cb40b5" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_8dbb730e-49b8-4f7d-a2e7-63e8e8f58eb9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_0634415c-3f28-4076-806e-056ca8a5aece" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_8dbb730e-49b8-4f7d-a2e7-63e8e8f58eb9" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_0634415c-3f28-4076-806e-056ca8a5aece" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_0634415c-3f28-4076-806e-056ca8a5aece_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0634415c-3f28-4076-806e-056ca8a5aece" xlink:to="loc_us-gaap_EquityComponentDomain_0634415c-3f28-4076-806e-056ca8a5aece_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_0634415c-3f28-4076-806e-056ca8a5aece" xlink:to="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_c7557d6a-e192-4536-9bbc-527ef53f6481" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_c7557d6a-e192-4536-9bbc-527ef53f6481" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_562f75c5-8c25-46c1-8fe9-24ed2c260bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_562f75c5-8c25-46c1-8fe9-24ed2c260bf9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_affbd2f3-4e52-40d3-a849-dc8b683bee6e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_affbd2f3-4e52-40d3-a849-dc8b683bee6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_0b30a047-f856-4322-bdd7-86083f6e7938" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e167d17a-b56c-43a4-836f-23322e57d984" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_0b30a047-f856-4322-bdd7-86083f6e7938" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_7179b770-3d8a-45fa-a572-3c9d03cb40b5" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_387d8235-5928-46fb-9112-3e982fec2480" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_387d8235-5928-46fb-9112-3e982fec2480" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_30a94576-fec0-4b02-b2dd-0598f880141d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_30a94576-fec0-4b02-b2dd-0598f880141d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_60585ae5-6647-4c56-aeab-0786a8cca3ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_60585ae5-6647-4c56-aeab-0786a8cca3ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_70423247-a14a-4b68-b58b-f700e1a49fa4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_260f6316-d992-45e8-96d2-205f292ce55f" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_70423247-a14a-4b68-b58b-f700e1a49fa4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_a2e930f9-d2fe-4ab7-9c8e-5c2ee778f0dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/FairValueMeasuresNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#FairValueMeasuresNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/FairValueMeasuresNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3caf6e6c-69c0-494a-9b1c-7a8899da6c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_fc3de585-f9ce-4049-8568-e0168cc62edc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3caf6e6c-69c0-494a-9b1c-7a8899da6c6e" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_fc3de585-f9ce-4049-8568-e0168cc62edc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_fc3de585-f9ce-4049-8568-e0168cc62edc" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a" xlink:to="loc_us-gaap_SegmentDomain_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_35c5865f-17d7-49b3-b105-bbc3942eb3d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_e06dfd6d-9bd5-40f1-ab2d-c4d628c0ea5a" xlink:to="loc_us-gaap_SegmentDomain_35c5865f-17d7-49b3-b105-bbc3942eb3d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AmericasSegmentMember_28e58a32-f1bc-4df3-9240-c5ae5ba33a3d" xlink:href="kwr-20241231.xsd#kwr_AmericasSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_35c5865f-17d7-49b3-b105-bbc3942eb3d9" xlink:to="loc_kwr_AmericasSegmentMember_28e58a32-f1bc-4df3-9240-c5ae5ba33a3d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_EMEASegmentMember_11f46991-3901-4ca5-962c-6c0c7cdecb8d" xlink:href="kwr-20241231.xsd#kwr_EMEASegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_35c5865f-17d7-49b3-b105-bbc3942eb3d9" xlink:to="loc_kwr_EMEASegmentMember_11f46991-3901-4ca5-962c-6c0c7cdecb8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AsiaPacificSegmentMember_7d9fa21f-7afe-4a15-8388-2cb9024d4743" xlink:href="kwr-20241231.xsd#kwr_AsiaPacificSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_35c5865f-17d7-49b3-b105-bbc3942eb3d9" xlink:to="loc_kwr_AsiaPacificSegmentMember_7d9fa21f-7afe-4a15-8388-2cb9024d4743" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_3ebc3d94-e36c-4393-a936-f6fca10dc630" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3caf6e6c-69c0-494a-9b1c-7a8899da6c6e" xlink:to="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_3ebc3d94-e36c-4393-a936-f6fca10dc630" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_PercentageOfWeightedAverageCostOfCapital_fd67020d-c97c-437f-a9e8-45d4bb1d4d05" xlink:href="kwr-20241231.xsd#kwr_PercentageOfWeightedAverageCostOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3caf6e6c-69c0-494a-9b1c-7a8899da6c6e" xlink:to="loc_kwr_PercentageOfWeightedAverageCostOfCapital_fd67020d-c97c-437f-a9e8-45d4bb1d4d05" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/HedgingActivitiesScheduleofNotionalAmountsofOutstandingDerivativePositionsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#HedgingActivitiesScheduleofNotionalAmountsofOutstandingDerivativePositionsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/HedgingActivitiesScheduleofNotionalAmountsofOutstandingDerivativePositionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_c47a21e0-97ab-40f1-b6d0-97cf486dccde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_817050dd-c7bf-41f4-9f0c-2f2fac09c923" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_c47a21e0-97ab-40f1-b6d0-97cf486dccde" xlink:to="loc_us-gaap_DerivativeTable_817050dd-c7bf-41f4-9f0c-2f2fac09c923" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CurrencyAxis_4a2e5775-d3a4-48e7-8306-b7b643af2155" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_CurrencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_817050dd-c7bf-41f4-9f0c-2f2fac09c923" xlink:to="loc_srt_CurrencyAxis_4a2e5775-d3a4-48e7-8306-b7b643af2155" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_AllCurrenciesDomain_4a2e5775-d3a4-48e7-8306-b7b643af2155_default" xlink:href="https://xbrl.sec.gov/currency/2024/currency-2024.xsd#currency_AllCurrenciesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CurrencyAxis_4a2e5775-d3a4-48e7-8306-b7b643af2155" xlink:to="loc_currency_AllCurrenciesDomain_4a2e5775-d3a4-48e7-8306-b7b643af2155_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_AllCurrenciesDomain_3c6b0c6d-075e-46d3-b62c-112d13e68c8e" xlink:href="https://xbrl.sec.gov/currency/2024/currency-2024.xsd#currency_AllCurrenciesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CurrencyAxis_4a2e5775-d3a4-48e7-8306-b7b643af2155" xlink:to="loc_currency_AllCurrenciesDomain_3c6b0c6d-075e-46d3-b62c-112d13e68c8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_MXN_bd2d18f8-725f-44fc-96f0-c115bf5041bd" xlink:href="https://xbrl.sec.gov/currency/2024/currency-2024.xsd#currency_MXN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_3c6b0c6d-075e-46d3-b62c-112d13e68c8e" xlink:to="loc_currency_MXN_bd2d18f8-725f-44fc-96f0-c115bf5041bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_currency_JPY_8b1cbbe3-353e-45fc-910c-dfb45eb63fe9" xlink:href="https://xbrl.sec.gov/currency/2024/currency-2024.xsd#currency_JPY"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_currency_AllCurrenciesDomain_3c6b0c6d-075e-46d3-b62c-112d13e68c8e" xlink:to="loc_currency_JPY_8b1cbbe3-353e-45fc-910c-dfb45eb63fe9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_8e17efe8-77fc-4cea-8912-ed22935aabf7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_c47a21e0-97ab-40f1-b6d0-97cf486dccde" xlink:to="loc_us-gaap_DerivativeNotionalAmount_8e17efe8-77fc-4cea-8912-ed22935aabf7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/HedgingActivitiesNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#HedgingActivitiesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/HedgingActivitiesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_1981a6da-15c0-4ccb-bf88-c8e81c7eb670" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_85950dca-e045-4352-92ef-007dce40bed8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_1981a6da-15c0-4ccb-bf88-c8e81c7eb670" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_85950dca-e045-4352-92ef-007dce40bed8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7bf565-aa35-4c2d-974b-77b02e6d2a56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_85950dca-e045-4352-92ef-007dce40bed8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7bf565-aa35-4c2d-974b-77b02e6d2a56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_bd7bf565-aa35-4c2d-974b-77b02e6d2a56_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7bf565-aa35-4c2d-974b-77b02e6d2a56" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_bd7bf565-aa35-4c2d-974b-77b02e6d2a56_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_28b1f8eb-e9e0-4feb-806f-1609ba5d730f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bd7bf565-aa35-4c2d-974b-77b02e6d2a56" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_28b1f8eb-e9e0-4feb-806f-1609ba5d730f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_83e1bb9c-1e16-4065-8ff6-ff0ae85f5bcb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28b1f8eb-e9e0-4feb-806f-1609ba5d730f" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_83e1bb9c-1e16-4065-8ff6-ff0ae85f5bcb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_0b2dace6-8aa4-469b-8957-f4882dde4f54" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28b1f8eb-e9e0-4feb-806f-1609ba5d730f" xlink:to="loc_us-gaap_InterestRateSwapMember_0b2dace6-8aa4-469b-8957-f4882dde4f54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_8dbaa14a-f0be-4968-a675-aadef8e73e8d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_1981a6da-15c0-4ccb-bf88-c8e81c7eb670" xlink:to="loc_us-gaap_DerivativeTermOfContract_8dbaa14a-f0be-4968-a675-aadef8e73e8d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_6e15dea6-ac9d-4583-b647-a7b9b1aa5f6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_1981a6da-15c0-4ccb-bf88-c8e81c7eb670" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_6e15dea6-ac9d-4583-b647-a7b9b1aa5f6b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/HedgingActivitiesScheduleofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#HedgingActivitiesScheduleofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/HedgingActivitiesScheduleofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5a9bb2d8-2956-4122-ab23-5220f480988b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_8608f259-382b-49d1-83ab-947bf2bdefae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5a9bb2d8-2956-4122-ab23-5220f480988b" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_8608f259-382b-49d1-83ab-947bf2bdefae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_2bbe1870-5dbf-4cb1-960c-fe9aedd88675" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_8608f259-382b-49d1-83ab-947bf2bdefae" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_2bbe1870-5dbf-4cb1-960c-fe9aedd88675" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2bbe1870-5dbf-4cb1-960c-fe9aedd88675_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_2bbe1870-5dbf-4cb1-960c-fe9aedd88675" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2bbe1870-5dbf-4cb1-960c-fe9aedd88675_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2858ca5c-1333-4500-9274-a2ce7a990a8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_2bbe1870-5dbf-4cb1-960c-fe9aedd88675" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2858ca5c-1333-4500-9274-a2ce7a990a8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_aba81bb3-0e39-4c8f-ab2b-f87857c31e8d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_2858ca5c-1333-4500-9274-a2ce7a990a8b" xlink:to="loc_us-gaap_InterestRateSwapMember_aba81bb3-0e39-4c8f-ab2b-f87857c31e8d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_8c382caf-a9ec-4b3c-b9bd-a8e51d742f53" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_2858ca5c-1333-4500-9274-a2ce7a990a8b" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_8c382caf-a9ec-4b3c-b9bd-a8e51d742f53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_242bfcdf-c31d-4268-b653-4de2f05c909f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_8608f259-382b-49d1-83ab-947bf2bdefae" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_242bfcdf-c31d-4268-b653-4de2f05c909f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_242bfcdf-c31d-4268-b653-4de2f05c909f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_242bfcdf-c31d-4268-b653-4de2f05c909f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_242bfcdf-c31d-4268-b653-4de2f05c909f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3938abb3-3916-4ce8-9f3d-595b5b50448a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_242bfcdf-c31d-4268-b653-4de2f05c909f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3938abb3-3916-4ce8-9f3d-595b5b50448a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_27317035-633e-4d8a-bff6-10a6a511b145" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_3938abb3-3916-4ce8-9f3d-595b5b50448a" xlink:to="loc_us-gaap_InterestExpenseMember_27317035-633e-4d8a-bff6-10a6a511b145" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseMember_e96ebd86-f525-4277-9924-e5b283e39874" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonoperatingIncomeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_3938abb3-3916-4ce8-9f3d-595b5b50448a" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseMember_e96ebd86-f525-4277-9924-e5b283e39874" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_24982b8b-9946-49ae-b493-104f8a3000e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_8608f259-382b-49d1-83ab-947bf2bdefae" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_24982b8b-9946-49ae-b493-104f8a3000e0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_24982b8b-9946-49ae-b493-104f8a3000e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_24982b8b-9946-49ae-b493-104f8a3000e0" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_24982b8b-9946-49ae-b493-104f8a3000e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_9f40aefe-ffe7-4c2e-818b-04a0b7c76e15" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationAxis_24982b8b-9946-49ae-b493-104f8a3000e0" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_9f40aefe-ffe7-4c2e-818b-04a0b7c76e15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_0b8ddec7-1ddb-45e6-80bc-71ab06973df2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_9f40aefe-ffe7-4c2e-818b-04a0b7c76e15" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_0b8ddec7-1ddb-45e6-80bc-71ab06973df2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncurrentAssetsMember_b5ab49ef-6617-4d4b-96b5-735a9a0936fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNoncurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementOfFinancialPositionLocationActivityCapitalizationDomain_9f40aefe-ffe7-4c2e-818b-04a0b7c76e15" xlink:to="loc_us-gaap_OtherNoncurrentAssetsMember_b5ab49ef-6617-4d4b-96b5-735a9a0936fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_21db4ae4-e7b9-4935-b2f1-66b0e95a1f2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5a9bb2d8-2956-4122-ab23-5220f480988b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax_21db4ae4-e7b9-4935-b2f1-66b0e95a1f2e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_6144537a-7878-4fa6-8280-65e7a7b21b45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5a9bb2d8-2956-4122-ab23-5220f480988b" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_6144537a-7878-4fa6-8280-65e7a7b21b45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_703c0e1a-dbc8-4b2e-956c-faacd82babb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5a9bb2d8-2956-4122-ab23-5220f480988b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_703c0e1a-dbc8-4b2e-956c-faacd82babb7" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.quakerchem.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="kwr-20241231.xsd#CommitmentsandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.quakerchem.com/role/CommitmentsandContingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_3b099b5b-1c37-4309-a4ed-2bc19ac10c5a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_f7334752-c103-43ad-a703-43d612484e71" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_3b099b5b-1c37-4309-a4ed-2bc19ac10c5a" xlink:to="loc_us-gaap_OtherCommitmentsTable_f7334752-c103-43ad-a703-43d612484e71" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b35d2aad-6296-4b4c-9c31-df467e281f80" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_f7334752-c103-43ad-a703-43d612484e71" xlink:to="loc_srt_RangeAxis_b35d2aad-6296-4b4c-9c31-df467e281f80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b35d2aad-6296-4b4c-9c31-df467e281f80_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b35d2aad-6296-4b4c-9c31-df467e281f80" xlink:to="loc_srt_RangeMember_b35d2aad-6296-4b4c-9c31-df467e281f80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_84ccc4db-4e3b-4c78-a28a-808555e8baa6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b35d2aad-6296-4b4c-9c31-df467e281f80" xlink:to="loc_srt_RangeMember_84ccc4db-4e3b-4c78-a28a-808555e8baa6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_2d9e7fb1-5ed5-4b62-a57a-517a6d6a074b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_84ccc4db-4e3b-4c78-a28a-808555e8baa6" xlink:to="loc_srt_MinimumMember_2d9e7fb1-5ed5-4b62-a57a-517a6d6a074b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_446d797a-c891-4df9-a0bd-ea278af3628e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_84ccc4db-4e3b-4c78-a28a-808555e8baa6" xlink:to="loc_srt_MaximumMember_446d797a-c891-4df9-a0bd-ea278af3628e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a1430c7b-388e-45ba-99d5-b304c8afa317" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_f7334752-c103-43ad-a703-43d612484e71" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a1430c7b-388e-45ba-99d5-b304c8afa317" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_a1430c7b-388e-45ba-99d5-b304c8afa317_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a1430c7b-388e-45ba-99d5-b304c8afa317" xlink:to="loc_us-gaap_LossContingencyNatureDomain_a1430c7b-388e-45ba-99d5-b304c8afa317_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_5370821b-146c-4b97-9375-fa98b4525d64" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_a1430c7b-388e-45ba-99d5-b304c8afa317" xlink:to="loc_us-gaap_LossContingencyNatureDomain_5370821b-146c-4b97-9375-fa98b4525d64" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AcpMember_e2d64f8a-3766-4680-806b-95140709af85" xlink:href="kwr-20241231.xsd#kwr_AcpMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_5370821b-146c-4b97-9375-fa98b4525d64" xlink:to="loc_kwr_AcpMember_e2d64f8a-3766-4680-806b-95140709af85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_HoughtonEnvironmentalMattersMember_cd6ec4bd-9206-4cd3-af6c-ed8a01cf978f" xlink:href="kwr-20241231.xsd#kwr_HoughtonEnvironmentalMattersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_5370821b-146c-4b97-9375-fa98b4525d64" xlink:to="loc_kwr_HoughtonEnvironmentalMattersMember_cd6ec4bd-9206-4cd3-af6c-ed8a01cf978f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_kwr_AsbestosClaimsMember_28783c4d-312b-4266-9e38-3f8a5aa37da7" xlink:href="kwr-20241231.xsd#kwr_AsbestosClaimsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_5370821b-146c-4b97-9375-fa98b4525d64" xlink:to="loc_kwr_AsbestosClaimsMember_28783c4d-312b-4266-9e38-3f8a5aa37da7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_0be903c4-c578-4ef1-a7db-c3a0eafa2e4e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_3b099b5b-1c37-4309-a4ed-2bc19ac10c5a" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_0be903c4-c578-4ef1-a7db-c3a0eafa2e4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_0f333dd2-4365-401b-95ca-5a22826c484c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_3b099b5b-1c37-4309-a4ed-2bc19ac10c5a" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_0f333dd2-4365-401b-95ca-5a22826c484c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainOnBusinessInterruptionInsuranceRecovery_f0c5ba75-e1c8-434b-bd5d-92eef19bd3a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainOnBusinessInterruptionInsuranceRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_3b099b5b-1c37-4309-a4ed-2bc19ac10c5a" xlink:to="loc_us-gaap_GainOnBusinessInterruptionInsuranceRecovery_f0c5ba75-e1c8-434b-bd5d-92eef19bd3a8" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-roles-2024.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc" order="101"/>
  </link:definitionLink>
</link:linkbase>
