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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019cb0c4-c659-7f42-b07a-89a9160cfbb4,g:198e6137-a549-4aca-96ac-beeecc07bdf6-->
<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.conocophillips.com/role/Cover" xlink:type="simple" xlink:href="cop-20260430.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.conocophillips.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019cb0c4-c659-7912-81a8-0dbdcb8c63fb" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:to="loc_dei_DocumentInformationTable_019cb0c4-c659-7912-81a8-0dbdcb8c63fb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019cb0c4-c659-7cdc-972c-73f9b77b878c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019cb0c4-c659-7912-81a8-0dbdcb8c63fb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019cb0c4-c659-7cdc-972c-73f9b77b878c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7cdc-972c-73f9b77b878c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cb0c4-c659-7cdc-972c-73f9b77b878c" xlink:to="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7cdc-972c-73f9b77b878c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7854-b23a-b03bd9f9b342" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019cb0c4-c659-7cdc-972c-73f9b77b878c" xlink:to="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7854-b23a-b03bd9f9b342" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019cb0c4-c659-7c66-a263-a4e94867121d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7854-b23a-b03bd9f9b342" xlink:to="loc_us-gaap_CommonStockMember_019cb0c4-c659-7c66-a263-a4e94867121d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_cop_SevenPercentDebenturesDueTwentyTwentyNineMember_019cb0c4-c659-7ad4-a5b9-2cac3a680860" xlink:href="cop-20260430.xsd#cop_SevenPercentDebenturesDueTwentyTwentyNineMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019cb0c4-c659-7854-b23a-b03bd9f9b342" xlink:to="loc_cop_SevenPercentDebenturesDueTwentyTwentyNineMember_019cb0c4-c659-7ad4-a5b9-2cac3a680860" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019cb0c4-c659-719d-be9b-cbad65e2f109" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:to="loc_dei_Security12bTitle_019cb0c4-c659-719d-be9b-cbad65e2f109" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019cb0c4-c659-7f92-b10e-3b1a283a9db2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:to="loc_dei_TradingSymbol_019cb0c4-c659-7f92-b10e-3b1a283a9db2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019cb0c4-c659-7ae3-b9ef-bda19579cd80" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:to="loc_dei_SecurityExchangeName_019cb0c4-c659-7ae3-b9ef-bda19579cd80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019cb0c4-c659-7e28-922d-4726f354e7ca" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_019cb0c4-c659-7be9-95df-45b98201e6a5" xlink:to="loc_dei_EntityRegistrantName_019cb0c4-c659-7e28-922d-4726f354e7ca" xlink:type="arc" order="3"/>
  </link:definitionLink>
</link:linkbase>
