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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e40e1-ab42-72ea-9272-282c249a7a37,g:99726f0f-47b2-460a-a518-29553d5bdb86-->
<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.10xgenomics.com/role/CoverPage" xlink:type="simple" xlink:href="txg-20260630.xsd#CoverPage"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/CoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_019e40e1-ac08-7c64-8bcb-c16a7cacf046" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentInformationTable_019e40e1-ac08-7c64-8bcb-c16a7cacf046" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-78b8-9f80-2826daf93f51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_019e40e1-ac08-7c64-8bcb-c16a7cacf046" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-78b8-9f80-2826daf93f51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-78b8-9f80-2826daf93f51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-78b8-9f80-2826daf93f51" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-78b8-9f80-2826daf93f51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7770-9402-1dfa40c0098d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-78b8-9f80-2826daf93f51" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7770-9402-1dfa40c0098d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e40e1-ac08-7863-bc87-75cf55e4d295" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7770-9402-1dfa40c0098d" xlink:to="loc_us-gaap_CommonClassAMember_019e40e1-ac08-7863-bc87-75cf55e4d295" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e40e1-ac08-744d-893c-246559b5c591" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7770-9402-1dfa40c0098d" xlink:to="loc_us-gaap_CommonClassBMember_019e40e1-ac08-744d-893c-246559b5c591" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e40e1-ac08-7d8f-8c6a-9bef345eb8e2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentType_019e40e1-ac08-7d8f-8c6a-9bef345eb8e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019e40e1-ac08-7787-806a-a49ee46bed2b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentQuarterlyReport_019e40e1-ac08-7787-806a-a49ee46bed2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019e40e1-ac08-794a-9781-a9dbe1c7e216" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentPeriodEndDate_019e40e1-ac08-794a-9781-a9dbe1c7e216" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019e40e1-ac08-7f2c-ac85-4adea9f14582" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentTransitionReport_019e40e1-ac08-7f2c-ac85-4adea9f14582" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019e40e1-ac08-7729-aff2-9c32e368af89" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityFileNumber_019e40e1-ac08-7729-aff2-9c32e368af89" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e40e1-ac08-79c3-9df6-367b92bde1a3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityRegistrantName_019e40e1-ac08-79c3-9df6-367b92bde1a3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019e40e1-ac08-7211-b800-5fda80b91768" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019e40e1-ac08-7211-b800-5fda80b91768" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e40e1-ac08-7bbb-b267-b01d551477e1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e40e1-ac08-7bbb-b267-b01d551477e1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019e40e1-ac08-7e14-9ce2-00df45d5d76d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityAddressAddressLine1_019e40e1-ac08-7e14-9ce2-00df45d5d76d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019e40e1-ac08-7b06-a8bb-52d6b827fd56" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityAddressCityOrTown_019e40e1-ac08-7b06-a8bb-52d6b827fd56" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019e40e1-ac08-7d9f-b17e-c02e37a17f74" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityAddressStateOrProvince_019e40e1-ac08-7d9f-b17e-c02e37a17f74" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019e40e1-ac08-78db-8dfb-5810cac2dfc3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityAddressPostalZipCode_019e40e1-ac08-78db-8dfb-5810cac2dfc3" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019e40e1-ac08-7cf9-95f5-e0371f4cfd18" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_CityAreaCode_019e40e1-ac08-7cf9-95f5-e0371f4cfd18" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019e40e1-ac08-7835-bc56-d07e7afe99ec" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_LocalPhoneNumber_019e40e1-ac08-7835-bc56-d07e7afe99ec" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019e40e1-ac08-76a2-8ea4-52a7c3146e47" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_Security12bTitle_019e40e1-ac08-76a2-8ea4-52a7c3146e47" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019e40e1-ac08-7ff9-986e-3ad0d1b93b65" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_TradingSymbol_019e40e1-ac08-7ff9-986e-3ad0d1b93b65" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019e40e1-ac08-7433-9bec-ecb5ca619d85" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_SecurityExchangeName_019e40e1-ac08-7433-9bec-ecb5ca619d85" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019e40e1-ac08-743b-84c1-54b1aac7e58e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityCurrentReportingStatus_019e40e1-ac08-743b-84c1-54b1aac7e58e" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019e40e1-ac08-74d1-b1dd-6bf62df35ef9" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityInteractiveDataCurrent_019e40e1-ac08-74d1-b1dd-6bf62df35ef9" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019e40e1-ac08-7684-9755-655503be935e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityFilerCategory_019e40e1-ac08-7684-9755-655503be935e" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019e40e1-ac08-7ff3-a2d8-aa1401d43f71" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntitySmallBusiness_019e40e1-ac08-7ff3-a2d8-aa1401d43f71" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019e40e1-ac08-78bb-8c91-30f662cd2682" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityEmergingGrowthCompany_019e40e1-ac08-78bb-8c91-30f662cd2682" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019e40e1-ac08-7337-afc3-0916920adb1f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityShellCompany_019e40e1-ac08-7337-afc3-0916920adb1f" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019e40e1-ac08-7ccd-b246-a55a54ed8e7a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019e40e1-ac08-7ccd-b246-a55a54ed8e7a" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e40e1-ac08-723d-bf23-cab5d530d1e6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_AmendmentFlag_019e40e1-ac08-723d-bf23-cab5d530d1e6" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019e40e1-ac08-77ab-8592-97dd9e0d1657" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentFiscalYearFocus_019e40e1-ac08-77ab-8592-97dd9e0d1657" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019e40e1-ac08-7fbf-9004-fd7cbc7c550e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019e40e1-ac08-7fbf-9004-fd7cbc7c550e" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019e40e1-ac08-7457-9772-45920ceeaa73" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_CurrentFiscalYearEndDate_019e40e1-ac08-7457-9772-45920ceeaa73" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e40e1-ac08-793d-bafa-4b1e53302291" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019e40e1-ac08-71d6-8a19-55318617be39" xlink:to="loc_dei_EntityCentralIndexKey_019e40e1-ac08-793d-bafa-4b1e53302291" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/CondensedConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="txg-20260630.xsd#CondensedConsolidatedStatementsofOperations"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/CondensedConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e40e1-ac08-7a78-9b87-ec02b9c6721e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_StatementTable_019e40e1-ac08-7a78-9b87-ec02b9c6721e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e40e1-ac08-7dd6-809f-09d87508ee2f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e40e1-ac08-7a78-9b87-ec02b9c6721e" xlink:to="loc_srt_ProductOrServiceAxis_019e40e1-ac08-7dd6-809f-09d87508ee2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-7dd6-809f-09d87508ee2f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e40e1-ac08-7dd6-809f-09d87508ee2f" xlink:to="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-7dd6-809f-09d87508ee2f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-70b4-8095-bed98ef3f385" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e40e1-ac08-7dd6-809f-09d87508ee2f" xlink:to="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-70b4-8095-bed98ef3f385" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProductAndServiceRevenueMember_019e40e1-ac08-7a5c-9ea0-ea10b56dfbf4" xlink:href="txg-20260630.xsd#txg_ProductAndServiceRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-70b4-8095-bed98ef3f385" xlink:to="loc_txg_ProductAndServiceRevenueMember_019e40e1-ac08-7a5c-9ea0-ea10b56dfbf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_LicensingAndRoyaltyRevenueMember_019e40e1-ac08-7cba-8554-ce16ed37dc58" xlink:href="txg-20260630.xsd#txg_LicensingAndRoyaltyRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e40e1-ac08-70b4-8095-bed98ef3f385" xlink:to="loc_txg_LicensingAndRoyaltyRevenueMember_019e40e1-ac08-7cba-8554-ce16ed37dc58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e40e1-ac08-753e-a26f-4f4f7da82c12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e40e1-ac08-753e-a26f-4f4f7da82c12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019e40e1-ac08-7ada-863e-31d1c2647531" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_CostOfRevenue_019e40e1-ac08-7ada-863e-31d1c2647531" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019e40e1-ac08-7591-b102-29fd798cbcd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_GrossProfit_019e40e1-ac08-7591-b102-29fd798cbcd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019e40e1-ac08-7201-97b5-8fa283acfe9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseExcludingAcquiredInProcessCost_019e40e1-ac08-7201-97b5-8fa283acfe9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019e40e1-ac08-70b2-ad3c-dabc74bf11c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019e40e1-ac08-70b2-ad3c-dabc74bf11c9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementGain_019e40e1-ac08-77e2-bd40-fee6fa2bb117" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LitigationSettlementGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:to="loc_us-gaap_LitigationSettlementGain_019e40e1-ac08-77e2-bd40-fee6fa2bb117" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019e40e1-ac08-733b-a883-befe2d4aff2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019e40e1-ac08-7b10-9e98-ce1850bf6614" xlink:to="loc_us-gaap_OperatingExpenses_019e40e1-ac08-733b-a883-befe2d4aff2f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019e40e1-ac08-7b02-ac98-2ab8ac308a81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_OperatingIncomeLoss_019e40e1-ac08-7b02-ac98-2ab8ac308a81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019e40e1-ac08-7eed-a090-4d787eea6a14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019e40e1-ac08-7eed-a090-4d787eea6a14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fad24-1e6c-72e8-876d-0b3e576e7eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fad24-1e6c-72e8-876d-0b3e576e7eb7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019e40e1-ac08-72f5-9ee3-8b3ae1cb4ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019e40e1-ac08-72f5-9ee3-8b3ae1cb4ea9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019e40e1-ac08-77d6-a08c-52a7335c7a0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019e40e1-ac08-7d0b-b370-283181ca8a6c" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019e40e1-ac08-77d6-a08c-52a7335c7a0a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e40e1-ac08-7a0b-b35a-eb49e8a0e539" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e40e1-ac08-7a0b-b35a-eb49e8a0e539" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e40e1-ac08-70bc-a14c-65e25051bf11" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e40e1-ac08-70bc-a14c-65e25051bf11" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e40e1-ac08-75bd-9d7b-f14803b5796f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_NetIncomeLoss_019e40e1-ac08-75bd-9d7b-f14803b5796f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019e40e1-ac08-74f9-b7c9-4fb73e5da05e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_EarningsPerShareBasic_019e40e1-ac08-74f9-b7c9-4fb73e5da05e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f1cf6-bde2-7eef-a4e3-4050b1d64b51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f1cf6-bde2-7eef-a4e3-4050b1d64b51" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e40e1-ac08-7472-8a98-8a2a0d6170b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019e40e1-ac08-7472-8a98-8a2a0d6170b1" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e40e1-ac08-7fc8-8068-23edbe772357" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7031-adae-95db36e54cef" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019e40e1-ac08-7fc8-8068-23edbe772357" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="simple" xlink:href="txg-20260630.xsd#CondensedConsolidatedStatementsofStockholdersEquity"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/CondensedConsolidatedStatementsofStockholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e40e1-ac08-7801-a2ad-b2377c0536ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e40e1-ac08-7571-a29b-34201cd56327" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7801-a2ad-b2377c0536ee" xlink:to="loc_us-gaap_StatementTable_019e40e1-ac08-7571-a29b-34201cd56327" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-7e75-ac09-c213459b7b6e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e40e1-ac08-7571-a29b-34201cd56327" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-7e75-ac09-c213459b7b6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7e75-ac09-c213459b7b6e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-7e75-ac09-c213459b7b6e" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-7e75-ac09-c213459b7b6e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-75e3-8802-65ccebddce6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-ac08-7e75-ac09-c213459b7b6e" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-75e3-8802-65ccebddce6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e40e1-ac08-7e7b-a3b5-6f8afa76bd47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-ac08-75e3-8802-65ccebddce6f" xlink:to="loc_us-gaap_CommonClassAMember_019e40e1-ac08-7e7b-a3b5-6f8afa76bd47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e40e1-ac08-735f-a35d-25c8e78ea379" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e40e1-ac08-7571-a29b-34201cd56327" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e40e1-ac08-735f-a35d-25c8e78ea379" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-735f-a35d-25c8e78ea379_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e40e1-ac08-735f-a35d-25c8e78ea379" xlink:to="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-735f-a35d-25c8e78ea379_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e40e1-ac08-735f-a35d-25c8e78ea379" xlink:to="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019e40e1-ac08-739e-bf7b-ffe4a6ae17ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:to="loc_us-gaap_CommonStockMember_019e40e1-ac08-739e-bf7b-ffe4a6ae17ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019e40e1-ac08-7f65-a0ca-8e7f1e31d818" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019e40e1-ac08-7f65-a0ca-8e7f1e31d818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019e40e1-ac08-7c4f-a1ea-238bf7119fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:to="loc_us-gaap_RetainedEarningsMember_019e40e1-ac08-7c4f-a1ea-238bf7119fd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e40e1-ac08-7581-8042-a9b6173a122c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e40e1-ac08-73ec-ac15-932d0067f6ce" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019e40e1-ac08-7581-8042-a9b6173a122c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e40e1-ac08-7801-a2ad-b2377c0536ee" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_019e40e1-ac08-7e7a-81e5-ae2eab2b110e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_SharesOutstanding_019e40e1-ac08-7e7a-81e5-ae2eab2b110e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e40e1-ac08-79b0-b087-e8e6b1819e3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_StockholdersEquity_019e40e1-ac08-79b0-b087-e8e6b1819e3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019e40e1-ac08-7610-b8a8-9df1c773999f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_019e40e1-ac08-7610-b8a8-9df1c773999f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019e40e1-ac08-7f4d-b5c4-d7af104850b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019e40e1-ac08-7f4d-b5c4-d7af104850b3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_StockIssuedDuringPeriodSharesContingentConsideration_019e40e1-ac08-71cf-93bd-aaa2b100d894" xlink:href="txg-20260630.xsd#txg_StockIssuedDuringPeriodSharesContingentConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_txg_StockIssuedDuringPeriodSharesContingentConsideration_019e40e1-ac08-71cf-93bd-aaa2b100d894" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_StockIssuedDuringPeriodValueContingentConsideration_019e40e1-ac08-7eca-9a89-3a0a82fa6ebc" xlink:href="txg-20260630.xsd#txg_StockIssuedDuringPeriodValueContingentConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_txg_StockIssuedDuringPeriodValueContingentConsideration_019e40e1-ac08-7eca-9a89-3a0a82fa6ebc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e40e1-ac08-706b-a922-9bdbe226f71f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e40e1-ac08-706b-a922-9bdbe226f71f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e40e1-ac08-7359-ab3e-e3827f002368" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_NetIncomeLoss_019e40e1-ac08-7359-ab3e-e3827f002368" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e40e1-ac08-7e94-a604-2bf8b146c24c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e40e1-ac08-7f91-a992-3fea538392c3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019e40e1-ac08-7e94-a604-2bf8b146c24c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_019e40e1-ac08-7f0d-9139-008759dbb580" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e40e1-ac08-70e6-9f35-8cec1efa627f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/AcquisitionAdditionalInformationDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#AcquisitionAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/AcquisitionAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f13cf-2690-7c3b-be98-358bd474ad2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f13cf-2690-7c3b-be98-358bd474ad2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f13cf-2690-7c3b-be98-358bd474ad2d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f13cf-2690-7c3b-be98-358bd474ad2d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f13cf-2690-7c3b-be98-358bd474ad2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f13cf-2690-7e53-9097-01553fb5326f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f13cf-2690-7c3b-be98-358bd474ad2d" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f13cf-2690-7e53-9097-01553fb5326f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProteintechGenomicsIncMember_019f13cf-2690-7493-9fbf-2d2468014fd6" xlink:href="txg-20260630.xsd#txg_ProteintechGenomicsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f13cf-2690-7e53-9097-01553fb5326f" xlink:to="loc_txg_ProteintechGenomicsIncMember_019f13cf-2690-7493-9fbf-2d2468014fd6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_019f5bde-5353-7675-b08d-0eecf253a222" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:to="loc_us-gaap_AssetAcquisitionAxis_019f5bde-5353-7675-b08d-0eecf253a222" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f5bde-5353-7675-b08d-0eecf253a222_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f5bde-5353-7675-b08d-0eecf253a222" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f5bde-5353-7675-b08d-0eecf253a222_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f5bde-5353-7fc2-b719-5637992b6f33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f5bde-5353-7675-b08d-0eecf253a222" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f5bde-5353-7fc2-b719-5637992b6f33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f5bde-7b08-71db-972b-eb7f833729b2" xlink:href="txg-20260630.xsd#txg_ScaleBioScienceInc.AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_019f5bde-5353-7fc2-b719-5637992b6f33" xlink:to="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f5bde-7b08-71db-972b-eb7f833729b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a" xlink:to="loc_us-gaap_ClassOfStockDomain_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019f5d99-c7e6-714e-85d1-93d969809969" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019f5d99-c7e6-7e5d-b0b4-ddf444e34d0a" xlink:to="loc_us-gaap_ClassOfStockDomain_019f5d99-c7e6-714e-85d1-93d969809969" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019f5d99-c7e6-7027-a702-5f077c6e99e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019f5d99-c7e6-714e-85d1-93d969809969" xlink:to="loc_us-gaap_CommonClassAMember_019f5d99-c7e6-7027-a702-5f077c6e99e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019fa571-52e1-723f-b394-e1c1b0b54c7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f13cf-2690-7a32-9274-fb4c9f7ed012" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019fa571-52e1-723f-b394-e1c1b0b54c7d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019fa571-52e1-723f-b394-e1c1b0b54c7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019fa571-52e1-723f-b394-e1c1b0b54c7d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019fa571-52e1-723f-b394-e1c1b0b54c7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019fa571-52e1-7ae3-a211-ae088a440533" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019fa571-52e1-723f-b394-e1c1b0b54c7d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019fa571-52e1-7ae3-a211-ae088a440533" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019fa571-52e1-77eb-87dc-25d2a4c9dcac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019fa571-52e1-7ae3-a211-ae088a440533" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019fa571-52e1-77eb-87dc-25d2a4c9dcac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f5bd6-dfe4-71ff-b73e-72137dd21cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f5bd6-dfe4-71ff-b73e-72137dd21cfe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019fa571-84bf-7318-9f07-20c828a68010" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019fa571-84bf-7318-9f07-20c828a68010" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_PrepaidSupplyRights_019f5bd8-0e2e-766f-9b2a-40e21e8c38ac" xlink:href="txg-20260630.xsd#txg_PrepaidSupplyRights"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_txg_PrepaidSupplyRights_019f5bd8-0e2e-766f-9b2a-40e21e8c38ac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_PrepaidSupplyRightsAmortizationPeriod_019fa578-4f11-74d5-a6ef-a2158a32c671" xlink:href="txg-20260630.xsd#txg_PrepaidSupplyRightsAmortizationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_txg_PrepaidSupplyRightsAmortizationPeriod_019fa578-4f11-74d5-a6ef-a2158a32c671" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa571-52e1-7390-81fa-bb56e62ead98" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa571-52e1-7390-81fa-bb56e62ead98" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8974-5f9d-7d03-b98f-adcc8c60f256" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8974-5f9d-7d03-b98f-adcc8c60f256" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_019fa575-c870-70e5-b0b0-84499b4366a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_019fa575-c870-70e5-b0b0-84499b4366a8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssued1_019fa575-c870-75ec-83bd-d23d1450adfc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssued1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_us-gaap_StockIssued1_019fa575-c870-75ec-83bd-d23d1450adfc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssetAcquisitionConsiderationTransferredEquityInterestShareIssuedNumberOfShares_019fa575-c870-76ef-a0e8-cbfe471542e1" xlink:href="txg-20260630.xsd#txg_AssetAcquisitionConsiderationTransferredEquityInterestShareIssuedNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_txg_AssetAcquisitionConsiderationTransferredEquityInterestShareIssuedNumberOfShares_019fa575-c870-76ef-a0e8-cbfe471542e1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximumAmount_019fa575-c870-7a47-85d7-dd3d8b0a96d6" xlink:href="txg-20260630.xsd#txg_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximumAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_txg_AssetAcquisitionContingentConsiderationRangeOfOutcomesMaximumAmount_019fa575-c870-7a47-85d7-dd3d8b0a96d6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_LiabilityCashPaymentToThirdParty_019fa575-df3e-7949-a2d7-2fbf8ca625fb" xlink:href="txg-20260630.xsd#txg_LiabilityCashPaymentToThirdParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f13cf-2690-7e07-8ef7-bd3e70c58d36" xlink:to="loc_txg_LiabilityCashPaymentToThirdParty_019fa575-df3e-7949-a2d7-2fbf8ca625fb" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/AcquisitionScheduleofAssetsAcquiredandLiabilitiesAssumedIncludingGoodwillandIntangiblesDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#AcquisitionScheduleofAssetsAcquiredandLiabilitiesAssumedIncludingGoodwillandIntangiblesDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/AcquisitionScheduleofAssetsAcquiredandLiabilitiesAssumedIncludingGoodwillandIntangiblesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e40e1-acdf-7bc4-8944-e7f89e68f4f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e40e1-acdf-7bc4-8944-e7f89e68f4f7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019e40e1-acdf-73c7-8c41-88d3b346ffcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e40e1-acdf-7bc4-8944-e7f89e68f4f7" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019e40e1-acdf-73c7-8c41-88d3b346ffcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e40e1-acdf-73c7-8c41-88d3b346ffcc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e40e1-acdf-73c7-8c41-88d3b346ffcc" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e40e1-acdf-73c7-8c41-88d3b346ffcc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e40e1-acdf-715e-914c-a2ef17ff428a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019e40e1-acdf-73c7-8c41-88d3b346ffcc" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e40e1-acdf-715e-914c-a2ef17ff428a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProteintechGenomicsIncMember_019f13cd-3ea4-754f-a64a-3dd5317117f9" xlink:href="txg-20260630.xsd#txg_ProteintechGenomicsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019e40e1-acdf-715e-914c-a2ef17ff428a" xlink:to="loc_txg_ProteintechGenomicsIncMember_019f13cd-3ea4-754f-a64a-3dd5317117f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1341-5093-7e4e-87f6-a44dc4fa0bb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019e40e1-acdf-7bc4-8944-e7f89e68f4f7" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1341-5093-7e4e-87f6-a44dc4fa0bb1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1341-5093-7e4e-87f6-a44dc4fa0bb1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1341-5093-7e4e-87f6-a44dc4fa0bb1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1341-5093-7e4e-87f6-a44dc4fa0bb1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1341-5093-7160-8ac8-ba018eb2c257" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1341-5093-7e4e-87f6-a44dc4fa0bb1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1341-5093-7160-8ac8-ba018eb2c257" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019f1341-6821-7167-957d-3e38545b6f47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1341-5093-7160-8ac8-ba018eb2c257" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019f1341-6821-7167-957d-3e38545b6f47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019fa805-08ff-7672-b481-5be5f5beb06e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019fa805-08ff-7672-b481-5be5f5beb06e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_019f13a0-3794-7142-8ec0-4c5788278f61" xlink:href="txg-20260630.xsd#txg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:to="loc_txg_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRightOfUseAssets_019f13a0-3794-7142-8ec0-4c5788278f61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f13a0-3794-7465-9593-70d863fa5430" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:to="loc_us-gaap_Goodwill_019f13a0-3794-7465-9593-70d863fa5430" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f13a0-3794-7616-8afb-47f6393e87b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019e40e1-acdf-7156-b4c6-f90fa3beaf56" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f13a0-3794-7616-8afb-47f6393e87b2" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/AcquisitionContingentConsiderationDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#AcquisitionContingentConsiderationDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/AcquisitionContingentConsiderationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f5be3-2a1f-706e-837c-7a85d5b677df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f5be3-2a1f-706e-837c-7a85d5b677df" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_019f5be3-2a1f-78ec-9574-c29be4b98606" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f5be3-2a1f-706e-837c-7a85d5b677df" xlink:to="loc_us-gaap_AssetAcquisitionAxis_019f5be3-2a1f-78ec-9574-c29be4b98606" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f5be3-2a1f-78ec-9574-c29be4b98606_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f5be3-2a1f-78ec-9574-c29be4b98606" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f5be3-2a1f-78ec-9574-c29be4b98606_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f5be3-2a1f-749f-8518-baf46a8a2565" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f5be3-2a1f-78ec-9574-c29be4b98606" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f5be3-2a1f-749f-8518-baf46a8a2565" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f5be3-2a1f-7481-a7c9-fd19e36be76e" xlink:href="txg-20260630.xsd#txg_ScaleBioScienceInc.AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_019f5be3-2a1f-749f-8518-baf46a8a2565" xlink:to="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f5be3-2a1f-7481-a7c9-fd19e36be76e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_019f5da3-49cd-7802-b445-a4bdc1e51512" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f5be3-2a1f-706e-837c-7a85d5b677df" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_019f5da3-49cd-7802-b445-a4bdc1e51512" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49cd-7802-b445-a4bdc1e51512_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019f5da3-49cd-7802-b445-a4bdc1e51512" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49cd-7802-b445-a4bdc1e51512_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49ce-7cad-8b50-cb5eb095a4ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_019f5da3-49cd-7802-b445-a4bdc1e51512" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49ce-7cad-8b50-cb5eb095a4ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ContingentConsiderationMember_019f5da3-49ce-790a-abfd-ee36a65d2f25" xlink:href="txg-20260630.xsd#txg_ContingentConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49ce-7cad-8b50-cb5eb095a4ea" xlink:to="loc_txg_ContingentConsiderationMember_019f5da3-49ce-790a-abfd-ee36a65d2f25" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssumedLiabilitiesMember_019f5da3-49ce-7645-96b3-ce09278494d8" xlink:href="txg-20260630.xsd#txg_AssumedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_019f5da3-49ce-7cad-8b50-cb5eb095a4ea" xlink:to="loc_txg_AssumedLiabilitiesMember_019f5da3-49ce-7645-96b3-ce09278494d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f5be3-2a1f-76f2-911c-705eb4c64c86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f5be3-2a1f-76f2-911c-705eb4c64c86" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersCash_019f5be3-2a1f-72cb-845c-8a19672afa82" xlink:href="txg-20260630.xsd#txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersCash_019f5be3-2a1f-72cb-845c-8a19672afa82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersEquity_019f5be3-2a1f-7b10-94dc-7b4de2d1668a" xlink:href="txg-20260630.xsd#txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_txg_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlementsSellersEquity_019f5be3-2a1f-7b10-94dc-7b4de2d1668a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_019f5be3-2a1f-7795-8380-2e120b051a31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements_019f5be3-2a1f-7795-8380-2e120b051a31" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f5be3-2a1f-7cfd-9a45-5f90532c90ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f5be3-2a1f-70a5-b4a8-9e8a08d8b390" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f5be3-2a1f-7cfd-9a45-5f90532c90ac" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f5be5-f967-7326-958a-a612381b739c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAvailableforSaleSecuritiesDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationAvailableforSaleSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAvailableforSaleSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesTable_019f1327-d166-7fb3-8a9f-268409b3c3bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_MarketableSecuritiesTable_019f1327-d166-7fb3-8a9f-268409b3c3bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019f1327-d166-7709-a156-3338ff478104" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_019f1327-d166-7fb3-8a9f-268409b3c3bb" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019f1327-d166-7709-a156-3338ff478104" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-7709-a156-3338ff478104_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019f1327-d166-7709-a156-3338ff478104" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-7709-a156-3338ff478104_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-74b8-b57c-d7b47a5c7f02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019f1327-d166-7709-a156-3338ff478104" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-74b8-b57c-d7b47a5c7f02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019f1327-d166-7113-90fd-e395b59b7df8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-74b8-b57c-d7b47a5c7f02" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019f1327-d166-7113-90fd-e395b59b7df8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentDebtSecuritiesMember_019f1327-d166-70a1-b16f-b411a2d65274" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019f1327-d166-74b8-b57c-d7b47a5c7f02" xlink:to="loc_us-gaap_USGovernmentDebtSecuritiesMember_019f1327-d166-70a1-b16f-b411a2d65274" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f1327-d166-72b2-b9ce-6f0affbdae92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_019f1327-d166-7fb3-8a9f-268409b3c3bb" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f1327-d166-72b2-b9ce-6f0affbdae92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-72b2-b9ce-6f0affbdae92_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f1327-d166-72b2-b9ce-6f0affbdae92" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-72b2-b9ce-6f0affbdae92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-7e23-91b7-b00368519d99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f1327-d166-72b2-b9ce-6f0affbdae92" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-7e23-91b7-b00368519d99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019f1327-d166-7509-ba05-b715292268bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-7e23-91b7-b00368519d99" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019f1327-d166-7509-ba05-b715292268bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019f1327-d166-764b-a14b-b4511ef97d99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f1327-d166-7e23-91b7-b00368519d99" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019f1327-d166-764b-a14b-b4511ef97d99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019f1327-d166-7ca3-a21b-e31081c6baa2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019f1327-d166-7ca3-a21b-e31081c6baa2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019f1327-d166-7d3a-b6df-dc36705a35cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_019f1327-d166-7d3a-b6df-dc36705a35cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019f1327-d166-7118-bb46-4f8e1f1d29de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019f1327-d166-7118-bb46-4f8e1f1d29de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019f1327-d166-74c0-95a5-185c17c16124" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019f1327-d166-74c0-95a5-185c17c16124" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019f1327-d166-7c55-a2e6-204437752bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019f1327-d166-7c55-a2e6-204437752bdd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_DebtSecuritiesAvailableForSaleAmortizedCostIncludingMoneyMarketFunds_019f1327-d166-7b82-a311-65d2e2199fe3" xlink:href="txg-20260630.xsd#txg_DebtSecuritiesAvailableForSaleAmortizedCostIncludingMoneyMarketFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_txg_DebtSecuritiesAvailableForSaleAmortizedCostIncludingMoneyMarketFunds_019f1327-d166-7b82-a311-65d2e2199fe3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_DebtSecuritiesAvailableForSaleIncludingMoneyMarketFunds_019f1327-d166-76e5-a370-d4569d8c27f1" xlink:href="txg-20260630.xsd#txg_DebtSecuritiesAvailableForSaleIncludingMoneyMarketFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f1327-d166-7d66-99d0-8d87f7f94906" xlink:to="loc_txg_DebtSecuritiesAvailableForSaleIncludingMoneyMarketFunds_019f1327-d166-76e5-a370-d4569d8c27f1" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleOfPropertyPlantAndEquipmentDetail" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationScheduleOfPropertyPlantAndEquipmentDetail"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleOfPropertyPlantAndEquipmentDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f1327-d166-7a53-9599-f21f59f96125" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f1327-d166-7043-8a99-2d69f338535b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f1327-d166-7a53-9599-f21f59f96125" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f1327-d166-7043-8a99-2d69f338535b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f1327-d166-736b-ab85-24fbeed527ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f1327-d166-7043-8a99-2d69f338535b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f1327-d166-736b-ab85-24fbeed527ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-736b-ab85-24fbeed527ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f1327-d166-736b-ab85-24fbeed527ce" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-736b-ab85-24fbeed527ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f1327-d166-736b-ab85-24fbeed527ce" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_019f1327-d166-7eae-b8ac-7a883f0d987c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_BuildingMember_019f1327-d166-7eae-b8ac-7a883f0d987c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019f1327-d166-75fb-8f60-55a86666f8b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019f1327-d166-75fb-8f60-55a86666f8b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_019f1327-d166-79ad-af8b-03b72243908a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_019f1327-d166-79ad-af8b-03b72243908a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_019f1327-d166-7324-81f6-9163221538b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_LandMember_019f1327-d166-7324-81f6-9163221538b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_019f1327-d166-77c0-b1ea-909050803b37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_ComputerEquipmentMember_019f1327-d166-77c0-b1ea-909050803b37" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019f1327-d166-7cba-9ed3-cadf5333cf8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019f1327-d166-7cba-9ed3-cadf5333cf8b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_019f1327-d166-71dc-916b-d018b3d0d57b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f1327-d166-78d9-8630-4939218ab43c" xlink:to="loc_us-gaap_ConstructionInProgressMember_019f1327-d166-71dc-916b-d018b3d0d57b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019f1327-d166-710f-b58f-cd50cf84759f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f1327-d166-7a53-9599-f21f59f96125" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019f1327-d166-710f-b58f-cd50cf84759f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019f1327-d166-7b52-a6e8-e841ea6c0969" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f1327-d166-7a53-9599-f21f59f96125" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019f1327-d166-7b52-a6e8-e841ea6c0969" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019f1327-d166-7e6e-b950-88c06806cfe1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f1327-d166-7a53-9599-f21f59f96125" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019f1327-d166-7e6e-b950-88c06806cfe1" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAdditionalInformationDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-75b9-a989-e15775897400_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-75b9-a989-e15775897400_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProductsAndServicesExcludingGrantRevenueMember_019f1327-d166-73bf-999f-1be8d76c2cf8" xlink:href="txg-20260630.xsd#txg_ProductsAndServicesExcludingGrantRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:to="loc_txg_ProductsAndServicesExcludingGrantRevenueMember_019f1327-d166-73bf-999f-1be8d76c2cf8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-78e2-b451-5cde27b6931c" xlink:href="txg-20260630.xsd#txg_LicensingAndRoyaltyRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:to="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-78e2-b451-5cde27b6931c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f1327-d166-7d66-a7ec-b82eeabbf583" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f1327-d166-7d66-a7ec-b82eeabbf583" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-73d4-a0f5-b5ef38f32cae_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-73d4-a0f5-b5ef38f32cae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TakaraBioUSAHoldingsInc.Member_019fcf4a-49e9-77e8-8d3d-3cf6cbd3f3f5" xlink:href="txg-20260630.xsd#txg_TakaraBioUSAHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_TakaraBioUSAHoldingsInc.Member_019fcf4a-49e9-77e8-8d3d-3cf6cbd3f3f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_VizgenInc.Member_019f1327-d166-70ad-9b7c-9843bded7450" xlink:href="txg-20260630.xsd#txg_VizgenInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_VizgenInc.Member_019f1327-d166-70ad-9b7c-9843bded7450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_BrukerCorporationMember_019f13ae-8cc0-7ebb-aa5c-99132427af6e" xlink:href="txg-20260630.xsd#txg_BrukerCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_BrukerCorporationMember_019f13ae-8cc0-7ebb-aa5c-99132427af6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-7530-90dd-4db313108d4b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-7530-90dd-4db313108d4b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f1327-d166-778b-af96-f91b235772b7" xlink:href="txg-20260630.xsd#txg_ScaleBioScienceInc.AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:to="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f1327-d166-778b-af96-f91b235772b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-7da2-9e1d-6477188f8545_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-7da2-9e1d-6477188f8545_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProteintechGenomicsIncMember_019f8968-c3cc-74a3-a302-a72bcdcf7a4a" xlink:href="txg-20260630.xsd#txg_ProteintechGenomicsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:to="loc_txg_ProteintechGenomicsIncMember_019f8968-c3cc-74a3-a302-a72bcdcf7a4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-7b27-9295-22461849f97f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-7b27-9295-22461849f97f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019f8968-c3cc-7847-a465-9a0bfd3387b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019f8968-c3cc-7847-a465-9a0bfd3387b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019f1327-d166-70e8-9d49-88e1064c051a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019f1327-d166-70e8-9d49-88e1064c051a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8922-9f59-7a3c-bd1f-8921405c7083" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8922-9f59-7a3c-bd1f-8921405c7083" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa565-0dfd-765b-9918-b3a7bad68e8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa565-0dfd-765b-9918-b3a7bad68e8e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_019f1327-d166-75f6-8e98-0edc3b7d78e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ContractWithCustomerLiability_019f1327-d166-75f6-8e98-0edc3b7d78e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019f1327-d166-72ea-8d1e-80ffd002255d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019f1327-d166-72ea-8d1e-80ffd002255d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f1327-d166-70a5-8d6c-300fc8f8e3b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f1327-d166-70a5-8d6c-300fc8f8e3b5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7f64-b8be-4961cfa062d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7f64-b8be-4961cfa062d0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax_019f1327-d166-746c-bdfa-2dd9998458fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax_019f1327-d166-746c-bdfa-2dd9998458fd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure_019f892c-0185-7380-b690-09631eebb2bc" xlink:href="txg-20260630.xsd#txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure_019f892c-0185-7380-b690-09631eebb2bc" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAdditionalInformationDetails_1" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationAdditionalInformationDetails_1"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationAdditionalInformationDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConcentrationRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-75b9-a989-e15775897400_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-75b9-a989-e15775897400_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-75b9-a989-e15775897400" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProductsAndServicesExcludingGrantRevenueMember_019f1327-d166-73bf-999f-1be8d76c2cf8" xlink:href="txg-20260630.xsd#txg_ProductsAndServicesExcludingGrantRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:to="loc_txg_ProductsAndServicesExcludingGrantRevenueMember_019f1327-d166-73bf-999f-1be8d76c2cf8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-78e2-b451-5cde27b6931c" xlink:href="txg-20260630.xsd#txg_LicensingAndRoyaltyRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ca9-93e3-9979cd135f2b" xlink:to="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-78e2-b451-5cde27b6931c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-73d4-a0f5-b5ef38f32cae_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-73d4-a0f5-b5ef38f32cae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019f1327-d166-73d4-a0f5-b5ef38f32cae" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TakaraBioUSAHoldingsInc.Member_019fcf4a-49e9-77e8-8d3d-3cf6cbd3f3f5" xlink:href="txg-20260630.xsd#txg_TakaraBioUSAHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_TakaraBioUSAHoldingsInc.Member_019fcf4a-49e9-77e8-8d3d-3cf6cbd3f3f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_VizgenInc.Member_019f1327-d166-70ad-9b7c-9843bded7450" xlink:href="txg-20260630.xsd#txg_VizgenInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_VizgenInc.Member_019f1327-d166-70ad-9b7c-9843bded7450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_BrukerCorporationMember_019f13ae-8cc0-7ebb-aa5c-99132427af6e" xlink:href="txg-20260630.xsd#txg_BrukerCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f1327-d166-79ae-b9ea-155ec4de2928" xlink:to="loc_txg_BrukerCorporationMember_019f13ae-8cc0-7ebb-aa5c-99132427af6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-7530-90dd-4db313108d4b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-7530-90dd-4db313108d4b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_019f1327-d166-7530-90dd-4db313108d4b" xlink:to="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f1327-d166-778b-af96-f91b235772b7" xlink:href="txg-20260630.xsd#txg_ScaleBioScienceInc.AcquisitionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_019f1327-d166-74df-8f2b-24ce7f324196" xlink:to="loc_txg_ScaleBioScienceInc.AcquisitionMember_019f1327-d166-778b-af96-f91b235772b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-7da2-9e1d-6477188f8545_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-7da2-9e1d-6477188f8545_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8968-c3cc-7da2-9e1d-6477188f8545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProteintechGenomicsIncMember_019f8968-c3cc-74a3-a302-a72bcdcf7a4a" xlink:href="txg-20260630.xsd#txg_ProteintechGenomicsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8968-c3cc-78c1-908f-51410c8ac51b" xlink:to="loc_txg_ProteintechGenomicsIncMember_019f8968-c3cc-74a3-a302-a72bcdcf7a4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConcentrationRiskTable_019f1327-d166-7430-87f6-d7eb0d897562" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-7b27-9295-22461849f97f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-7b27-9295-22461849f97f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8968-c3cc-7b27-9295-22461849f97f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019f8968-c3cc-7847-a465-9a0bfd3387b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8968-c3cc-750b-9d19-743c02aae397" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019f8968-c3cc-7847-a465-9a0bfd3387b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019f1327-d166-70e8-9d49-88e1064c051a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_019f1327-d166-70e8-9d49-88e1064c051a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8922-9f59-7a3c-bd1f-8921405c7083" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8922-9f59-7a3c-bd1f-8921405c7083" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa565-0dfd-765b-9918-b3a7bad68e8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019fa565-0dfd-765b-9918-b3a7bad68e8e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_019f1327-d166-75f6-8e98-0edc3b7d78e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ContractWithCustomerLiability_019f1327-d166-75f6-8e98-0edc3b7d78e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019f1327-d166-72ea-8d1e-80ffd002255d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019f1327-d166-72ea-8d1e-80ffd002255d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f1327-d166-70a5-8d6c-300fc8f8e3b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f1327-d166-70a5-8d6c-300fc8f8e3b5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7f64-b8be-4961cfa062d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7f64-b8be-4961cfa062d0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax_019f1327-d166-746c-bdfa-2dd9998458fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealizedAfterTax_019f1327-d166-746c-bdfa-2dd9998458fd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure_019f892c-0185-7380-b690-09631eebb2bc" xlink:href="txg-20260630.xsd#txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_019f1327-d166-774b-8c35-9e8c5534bf01" xlink:to="loc_txg_AssetAcquisitionGainLossContingentConsiderationChangeInFairValueDisclosure_019f892c-0185-7380-b690-09631eebb2bc" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationIntangibleAssetsNetDetail" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationIntangibleAssetsNetDetail"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationIntangibleAssetsNetDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f1327-d166-7b93-a4f8-782c529a44a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f1327-d166-7b93-a4f8-782c529a44a2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1327-d166-7374-97f7-dd2291f4ecc1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f1327-d166-7b93-a4f8-782c529a44a2" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1327-d166-7374-97f7-dd2291f4ecc1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-7374-97f7-dd2291f4ecc1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1327-d166-7374-97f7-dd2291f4ecc1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-7374-97f7-dd2291f4ecc1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f1327-d166-7374-97f7-dd2291f4ecc1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_019f1327-d166-7eb6-a26e-ffe729901685" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_019f1327-d166-7eb6-a26e-ffe729901685" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TechnologyLicensesMember_019f1327-d166-7d15-bb7d-da8799ba5b81" xlink:href="txg-20260630.xsd#txg_TechnologyLicensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:to="loc_txg_TechnologyLicensesMember_019f1327-d166-7d15-bb7d-da8799ba5b81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AssembledWorkforceMember_019f1327-d166-7a35-bc14-66f5ad6aac7a" xlink:href="txg-20260630.xsd#txg_AssembledWorkforceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:to="loc_txg_AssembledWorkforceMember_019f1327-d166-7a35-bc14-66f5ad6aac7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f1327-d166-7063-88ff-5008f9c49255" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f1327-d166-784c-91cd-625f757823b1" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f1327-d166-7063-88ff-5008f9c49255" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019f1327-d166-75f6-af0a-970d9be2331d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019f1327-d166-75f6-af0a-970d9be2331d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f1327-d166-75ce-b1b9-4dd043fb984e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f1327-d166-75ce-b1b9-4dd043fb984e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f1327-d166-7a20-b73a-b48585722257" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f1327-d166-7a20-b73a-b48585722257" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f1327-d166-7442-9126-dfdc196620a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f1327-d166-7ddf-83b2-fdd094e224f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f1327-d166-7442-9126-dfdc196620a0" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleofRevenuebySourceDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationScheduleofRevenuebySourceDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleofRevenuebySourceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019f1327-d166-7490-bf60-91ac7701cf45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019f1327-d166-7b00-abe1-52cb5c306c43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019f1327-d166-7490-bf60-91ac7701cf45" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019f1327-d166-7b00-abe1-52cb5c306c43" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f1327-d166-7d5a-bcd9-da1909d842a7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_019f1327-d166-7b00-abe1-52cb5c306c43" xlink:to="loc_srt_ProductOrServiceAxis_019f1327-d166-7d5a-bcd9-da1909d842a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-7d5a-bcd9-da1909d842a7_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-7d5a-bcd9-da1909d842a7" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-7d5a-bcd9-da1909d842a7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f1327-d166-7d5a-bcd9-da1909d842a7" xlink:to="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_InstrumentsMember_019f1327-d166-7d06-a8b0-51c6ae1f289b" xlink:href="txg-20260630.xsd#txg_InstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:to="loc_txg_InstrumentsMember_019f1327-d166-7d06-a8b0-51c6ae1f289b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ChromiumInstrumentsMember_019f1327-d166-7f04-b6a3-f05097549a3c" xlink:href="txg-20260630.xsd#txg_ChromiumInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_txg_InstrumentsMember_019f1327-d166-7d06-a8b0-51c6ae1f289b" xlink:to="loc_txg_ChromiumInstrumentsMember_019f1327-d166-7f04-b6a3-f05097549a3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_SpatialInstrumentsMember_019f1327-d166-7bba-b9ee-1622e3fd3140" xlink:href="txg-20260630.xsd#txg_SpatialInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_txg_InstrumentsMember_019f1327-d166-7d06-a8b0-51c6ae1f289b" xlink:to="loc_txg_SpatialInstrumentsMember_019f1327-d166-7bba-b9ee-1622e3fd3140" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ConsumablesMember_019f1327-d166-75d3-83c1-d1926d861a11" xlink:href="txg-20260630.xsd#txg_ConsumablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:to="loc_txg_ConsumablesMember_019f1327-d166-75d3-83c1-d1926d861a11" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ChromiumConsumablesMember_019f1327-d166-704d-8dd7-217aa27ab52c" xlink:href="txg-20260630.xsd#txg_ChromiumConsumablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_txg_ConsumablesMember_019f1327-d166-75d3-83c1-d1926d861a11" xlink:to="loc_txg_ChromiumConsumablesMember_019f1327-d166-704d-8dd7-217aa27ab52c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_SpatialConsumablesMember_019f1327-d166-7213-869f-038adae67dde" xlink:href="txg-20260630.xsd#txg_SpatialConsumablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_txg_ConsumablesMember_019f1327-d166-75d3-83c1-d1926d861a11" xlink:to="loc_txg_SpatialConsumablesMember_019f1327-d166-7213-869f-038adae67dde" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019f1327-d166-7d94-bd12-f7778843c589" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:to="loc_us-gaap_ServiceMember_019f1327-d166-7d94-bd12-f7778843c589" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ProductAndServiceRevenueMember_019f1327-d166-790a-9482-97e435f02f82" xlink:href="txg-20260630.xsd#txg_ProductAndServiceRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:to="loc_txg_ProductAndServiceRevenueMember_019f1327-d166-790a-9482-97e435f02f82" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-7c11-a275-deaac8fcb1b9" xlink:href="txg-20260630.xsd#txg_LicensingAndRoyaltyRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f1327-d166-7ec3-bafe-9adb9fde89fb" xlink:to="loc_txg_LicensingAndRoyaltyRevenueMember_019f1327-d166-7c11-a275-deaac8fcb1b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-74fa-aa86-0ac5e4a24980" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_019f1327-d166-7490-bf60-91ac7701cf45" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-74fa-aa86-0ac5e4a24980" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleofRevenuebyGeographicRegionDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#OtherFinancialStatementInformationScheduleofRevenuebyGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/OtherFinancialStatementInformationScheduleofRevenuebyGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f1327-d166-72a1-a290-807208ed519c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f1327-d166-76df-8f8b-72b3c0f324e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f1327-d166-72a1-a290-807208ed519c" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f1327-d166-76df-8f8b-72b3c0f324e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019f1327-d166-7888-9429-a5923b0ed862" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f1327-d166-76df-8f8b-72b3c0f324e9" xlink:to="loc_srt_StatementGeographicalAxis_019f1327-d166-7888-9429-a5923b0ed862" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f1327-d166-7888-9429-a5923b0ed862_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019f1327-d166-7888-9429-a5923b0ed862" xlink:to="loc_srt_SegmentGeographicalDomain_019f1327-d166-7888-9429-a5923b0ed862_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f1327-d166-77d3-a1e3-41234e995c16" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019f1327-d166-7888-9429-a5923b0ed862" xlink:to="loc_srt_SegmentGeographicalDomain_019f1327-d166-77d3-a1e3-41234e995c16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_019f1327-d166-7435-b534-20cb44b34f55" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f1327-d166-77d3-a1e3-41234e995c16" xlink:to="loc_srt_AmericasMember_019f1327-d166-7435-b534-20cb44b34f55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019f1327-d166-7dc2-a75d-ebd7eee8db03" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AmericasMember_019f1327-d166-7435-b534-20cb44b34f55" xlink:to="loc_country_US_019f1327-d166-7dc2-a75d-ebd7eee8db03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AmericasExcludingUnitedStatesMember_019f1327-d166-7483-b8f3-1ed9df138667" xlink:href="txg-20260630.xsd#txg_AmericasExcludingUnitedStatesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AmericasMember_019f1327-d166-7435-b534-20cb44b34f55" xlink:to="loc_txg_AmericasExcludingUnitedStatesMember_019f1327-d166-7483-b8f3-1ed9df138667" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_019f1327-d166-70ab-a83b-5a671ccff27d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f1327-d166-77d3-a1e3-41234e995c16" xlink:to="loc_us-gaap_EMEAMember_019f1327-d166-70ab-a83b-5a671ccff27d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019f1327-d166-7842-a705-07f6002ee3c2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f1327-d166-77d3-a1e3-41234e995c16" xlink:to="loc_srt_AsiaPacificMember_019f1327-d166-7842-a705-07f6002ee3c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_019f1327-d166-70c9-a6f2-5a6af59c1f73" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AsiaPacificMember_019f1327-d166-7842-a705-07f6002ee3c2" xlink:to="loc_country_CN_019f1327-d166-70c9-a6f2-5a6af59c1f73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AsiaPacificExcludingChinaMember_019f1327-d166-74a4-97e3-4e96c8a40b3b" xlink:href="txg-20260630.xsd#txg_AsiaPacificExcludingChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AsiaPacificMember_019f1327-d166-7842-a705-07f6002ee3c2" xlink:to="loc_txg_AsiaPacificExcludingChinaMember_019f1327-d166-74a4-97e3-4e96c8a40b3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7e9d-aba4-7b757f0c47f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f1327-d166-72a1-a290-807208ed519c" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f1327-d166-7e9d-aba4-7b757f0c47f3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/CapitalStockAdditionalInformationDetail" xlink:type="simple" xlink:href="txg-20260630.xsd#CapitalStockAdditionalInformationDetail"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/CapitalStockAdditionalInformationDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019e40e1-acdf-79db-9505-a6d9b897095c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019e40e1-acdf-7688-b027-81430ce51aad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e40e1-acdf-79db-9505-a6d9b897095c" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019e40e1-acdf-7688-b027-81430ce51aad" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-76ff-83f0-5a7c9731ed17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019e40e1-acdf-7688-b027-81430ce51aad" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-76ff-83f0-5a7c9731ed17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-76ff-83f0-5a7c9731ed17_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-76ff-83f0-5a7c9731ed17" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-76ff-83f0-5a7c9731ed17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-71af-a441-37d389f5f566" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-76ff-83f0-5a7c9731ed17" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-71af-a441-37d389f5f566" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e40e1-acdf-74cd-afb5-fa648e8c874f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-71af-a441-37d389f5f566" xlink:to="loc_us-gaap_CommonClassAMember_019e40e1-acdf-74cd-afb5-fa648e8c874f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_019e40e1-acdf-77a2-8daf-3d2808d3f0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-71af-a441-37d389f5f566" xlink:to="loc_us-gaap_CommonClassBMember_019e40e1-acdf-77a2-8daf-3d2808d3f0a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019e40e1-acdf-7408-8ea3-c53c5014b978" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e40e1-acdf-79db-9505-a6d9b897095c" xlink:to="loc_us-gaap_CommonStockSharesIssued_019e40e1-acdf-7408-8ea3-c53c5014b978" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019e40e1-acdf-7a0e-bb50-49718f215567" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019e40e1-acdf-79db-9505-a6d9b897095c" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019e40e1-acdf-7a0e-bb50-49718f215567" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e40e1-acdf-71bb-875f-8483b4ce7da4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e40e1-acdf-71bb-875f-8483b4ce7da4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e40e1-acdf-7add-9c42-7e751c66e533" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e40e1-acdf-71bb-875f-8483b4ce7da4" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e40e1-acdf-7add-9c42-7e751c66e533" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e40e1-acdf-76f3-b577-c250112c423f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e40e1-acdf-76f3-b577-c250112c423f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails_1" xlink:type="simple" xlink:href="txg-20260630.xsd#EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails_1"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/EquityIncentivePlansScheduleofRecordedStockBasedCompensationExpenseintheCondensedConsolidatedStatementofOperationsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e40e1-acdf-71bb-875f-8483b4ce7da4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e40e1-acdf-71bb-875f-8483b4ce7da4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e40e1-acdf-76f3-b577-c250112c423f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e40e1-acdf-70ef-848c-2a6780b1c2b1" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e40e1-acdf-76f3-b577-c250112c423f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/EquityIncentivePlansAdditionalInformationDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#EquityIncentivePlansAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/EquityIncentivePlansAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-742a-a2bc-ec19e19b51ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:to="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-742a-a2bc-ec19e19b51ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-742a-a2bc-ec19e19b51ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-742a-a2bc-ec19e19b51ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-742a-a2bc-ec19e19b51ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-742a-a2bc-ec19e19b51ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019e40e1-acdf-7ef0-b802-04a6efb16e87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:to="loc_us-gaap_PerformanceSharesMember_019e40e1-acdf-7ef0-b802-04a6efb16e87" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_CompoundAnnualGrowthRateMember_019e40e1-acdf-750c-8362-cf57b60f5d9a" xlink:href="txg-20260630.xsd#txg_CompoundAnnualGrowthRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:to="loc_txg_CompoundAnnualGrowthRateMember_019e40e1-acdf-750c-8362-cf57b60f5d9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TotalShareholderReturnMember_019e40e1-acdf-7cc0-ad6b-66a333a4b6ee" xlink:href="txg-20260630.xsd#txg_TotalShareholderReturnMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:to="loc_txg_TotalShareholderReturnMember_019e40e1-acdf-7cc0-ad6b-66a333a4b6ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockMember_019e40e1-acdf-7588-8490-8831a4aaf81b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7c2d-8af0-bf8bbb16129c" xlink:to="loc_us-gaap_EmployeeStockMember_019e40e1-acdf-7588-8490-8831a4aaf81b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019e40e1-acdf-7b88-ab92-d5f5848b35d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:to="loc_us-gaap_PlanNameAxis_019e40e1-acdf-7b88-ab92-d5f5848b35d5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019e40e1-acdf-7b88-ab92-d5f5848b35d5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019e40e1-acdf-7b88-ab92-d5f5848b35d5" xlink:to="loc_us-gaap_PlanNameDomain_019e40e1-acdf-7b88-ab92-d5f5848b35d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019e40e1-acdf-79da-9a14-3cc598ccef63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019e40e1-acdf-7b88-ab92-d5f5848b35d5" xlink:to="loc_us-gaap_PlanNameDomain_019e40e1-acdf-79da-9a14-3cc598ccef63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TwoThousandsNineteenPlanMember_019e40e1-acdf-7f38-b599-58e7251611d2" xlink:href="txg-20260630.xsd#txg_TwoThousandsNineteenPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019e40e1-acdf-79da-9a14-3cc598ccef63" xlink:to="loc_txg_TwoThousandsNineteenPlanMember_019e40e1-acdf-7f38-b599-58e7251611d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_MarketBasedPerformanceAwardsMember_019e40e1-acdf-7c14-ad26-661435e43eba" xlink:href="txg-20260630.xsd#txg_MarketBasedPerformanceAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019e40e1-acdf-79da-9a14-3cc598ccef63" xlink:to="loc_txg_MarketBasedPerformanceAwardsMember_019e40e1-acdf-7c14-ad26-661435e43eba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_TwoThousandsNineteenEmployeeStockPurchasePlanMember_019e40e1-acdf-72a1-bf17-94309ec6f81c" xlink:href="txg-20260630.xsd#txg_TwoThousandsNineteenEmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019e40e1-acdf-79da-9a14-3cc598ccef63" xlink:to="loc_txg_TwoThousandsNineteenEmployeeStockPurchasePlanMember_019e40e1-acdf-72a1-bf17-94309ec6f81c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-7142-a7cc-cfe48832f392" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-7142-a7cc-cfe48832f392" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-7142-a7cc-cfe48832f392_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-7142-a7cc-cfe48832f392" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-7142-a7cc-cfe48832f392_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-7cee-ae59-8a6de84d62cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019e40e1-acdf-7142-a7cc-cfe48832f392" xlink:to="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-7cee-ae59-8a6de84d62cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_019e40e1-acdf-7222-a7ff-12f955b4fa14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019e40e1-acdf-7cee-ae59-8a6de84d62cc" xlink:to="loc_us-gaap_CommonClassAMember_019e40e1-acdf-7222-a7ff-12f955b4fa14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019e40e1-acdf-78a9-bcc2-8c395dc6bac3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7f76-b03a-a378fa27bf58" xlink:to="loc_srt_RangeAxis_019e40e1-acdf-78a9-bcc2-8c395dc6bac3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e40e1-acdf-78a9-bcc2-8c395dc6bac3_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019e40e1-acdf-78a9-bcc2-8c395dc6bac3" xlink:to="loc_srt_RangeMember_019e40e1-acdf-78a9-bcc2-8c395dc6bac3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019e40e1-acdf-7816-b986-035bb0fcc76f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019e40e1-acdf-78a9-bcc2-8c395dc6bac3" xlink:to="loc_srt_RangeMember_019e40e1-acdf-7816-b986-035bb0fcc76f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019e40e1-acdf-7a94-8aa6-b29a729b46bd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e40e1-acdf-7816-b986-035bb0fcc76f" xlink:to="loc_srt_MinimumMember_019e40e1-acdf-7a94-8aa6-b29a729b46bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019e40e1-acdf-7659-9ac3-f5c7d68c314e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019e40e1-acdf-7816-b986-035bb0fcc76f" xlink:to="loc_srt_MaximumMember_019e40e1-acdf-7659-9ac3-f5c7d68c314e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019e40e1-acdf-7165-a452-54d654528412" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019e40e1-acdf-7165-a452-54d654528412" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019e40e1-acdf-7058-a842-e307c3dd5cba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019e40e1-acdf-7058-a842-e307c3dd5cba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019e40e1-acdf-72c3-a761-e4c67359aa70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019e40e1-acdf-72c3-a761-e4c67359aa70" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsMultiplierPercentage_019e40e1-acdf-7be3-b304-ff8d7035124e" xlink:href="txg-20260630.xsd#txg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsMultiplierPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_txg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsMultiplierPercentage_019e40e1-acdf-7be3-b304-ff8d7035124e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019e40e1-acdf-7ae8-a3a0-a534d4564276" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019e40e1-acdf-7ae8-a3a0-a534d4564276" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_019e40e1-acdf-7bda-9b45-f797ea5ce5c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_019e40e1-acdf-7bda-9b45-f797ea5ce5c4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019e40e1-acdf-7ae3-890e-c367d8d158bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_019e40e1-acdf-7ae3-890e-c367d8d158bc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019e40e1-acdf-7268-9db8-34314d616e8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_019e40e1-acdf-7268-9db8-34314d616e8c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019e40e1-acdf-7eb3-bd95-534511a8d32d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-716c-a954-4037f0a686df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019e40e1-acdf-7eb3-bd95-534511a8d32d" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/EquityIncentivePlansFairValuesofSharesUnderthePerformanceStockUnitsDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#EquityIncentivePlansFairValuesofSharesUnderthePerformanceStockUnitsDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/EquityIncentivePlansFairValuesofSharesUnderthePerformanceStockUnitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-7032-994b-da880da0fedc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7bab-afad-3cc892ef5335" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-7032-994b-da880da0fedc" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7bab-afad-3cc892ef5335" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-7193-842a-5266df8d0f5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e40e1-acdf-7bab-afad-3cc892ef5335" xlink:to="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-7193-842a-5266df8d0f5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7193-842a-5266df8d0f5a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-7193-842a-5266df8d0f5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-7193-842a-5266df8d0f5a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-71aa-9079-d7368da4ad2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e40e1-acdf-7193-842a-5266df8d0f5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-71aa-9079-d7368da4ad2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019e40e1-acdf-74a0-9cb3-17fe55ee215b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e40e1-acdf-71aa-9079-d7368da4ad2d" xlink:to="loc_us-gaap_PerformanceSharesMember_019e40e1-acdf-74a0-9cb3-17fe55ee215b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019e40e1-acdf-7629-b075-8313c5307cc8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-7032-994b-da880da0fedc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019e40e1-acdf-7629-b075-8313c5307cc8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019e40e1-acdf-78af-9f52-4c2cb8e336da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-7032-994b-da880da0fedc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019e40e1-acdf-78af-9f52-4c2cb8e336da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019e40e1-acdf-7c04-ac1e-7c130abfdfad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e40e1-acdf-7032-994b-da880da0fedc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019e40e1-acdf-7c04-ac1e-7c130abfdfad" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.10xgenomics.com/role/NetIncomeLossPerShareSharesofCommonStockEquivalentsWereExcludedFromTheComputationofDilutedNetLossPerShareDetails" xlink:type="simple" xlink:href="txg-20260630.xsd#NetIncomeLossPerShareSharesofCommonStockEquivalentsWereExcludedFromTheComputationofDilutedNetLossPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.10xgenomics.com/role/NetIncomeLossPerShareSharesofCommonStockEquivalentsWereExcludedFromTheComputationofDilutedNetLossPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019e40e1-acdf-7126-8d29-5792ad3115e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019e40e1-acdf-78f2-8dcf-66a5276302e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019e40e1-acdf-7126-8d29-5792ad3115e6" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019e40e1-acdf-78f2-8dcf-66a5276302e1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019e40e1-acdf-7b65-96de-4588fdbfff85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019e40e1-acdf-78f2-8dcf-66a5276302e1" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019e40e1-acdf-7b65-96de-4588fdbfff85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7b65-96de-4588fdbfff85_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019e40e1-acdf-7b65-96de-4588fdbfff85" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7b65-96de-4588fdbfff85_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7249-b292-c934aad26806" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019e40e1-acdf-7b65-96de-4588fdbfff85" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7249-b292-c934aad26806" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e40e1-acdf-7620-bcf7-d74212f0b656" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7249-b292-c934aad26806" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e40e1-acdf-7620-bcf7-d74212f0b656" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_StockOptionsRestrictedStockAndEmployeeStockPurchasePlanMember_019e40e1-acdf-7391-b3de-af88170629d5" xlink:href="txg-20260630.xsd#txg_StockOptionsRestrictedStockAndEmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7249-b292-c934aad26806" xlink:to="loc_txg_StockOptionsRestrictedStockAndEmployeeStockPurchasePlanMember_019e40e1-acdf-7391-b3de-af88170629d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_SharesUnderEsppPlanMember_019e40e1-acdf-7754-874c-eb950adb1a17" xlink:href="txg-20260630.xsd#txg_SharesUnderEsppPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019e40e1-acdf-7249-b292-c934aad26806" xlink:to="loc_txg_SharesUnderEsppPlanMember_019e40e1-acdf-7754-874c-eb950adb1a17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019e40e1-acdf-796f-ac6e-32f75d096b18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019e40e1-acdf-7126-8d29-5792ad3115e6" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019e40e1-acdf-796f-ac6e-32f75d096b18" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_SarahTeichmannMember_019e40e1-ab42-74a9-9fb7-527d36bf15df" xlink:href="txg-20260630.xsd#txg_SarahTeichmannMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_txg_SarahTeichmannMember_019e40e1-ab42-74a9-9fb7-527d36bf15df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_txg_AdamTaichMember_019fa542-928a-70c6-996a-bd521b039f08" xlink:href="txg-20260630.xsd#txg_AdamTaichMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_txg_AdamTaichMember_019fa542-928a-70c6-996a-bd521b039f08" xlink:type="arc" order="3"/>
  </link:definitionLink>
</link:linkbase>
