<?xml version="1.0" encoding="UTF-8"?>
<npx:edgarSubmission xmlns:npx="http://www.sec.gov/edgar/npx" xmlns:common="http://www.sec.gov/edgar/common" xmlns:iso_statecodes="http://www.sec.gov/edgar/iso_statecodes">
  <npx:headerData>
    <npx:submissionType>N-PX</npx:submissionType>
    <npx:filerInfo>
      <npx:registrantType>IM</npx:registrantType>
      <npx:liveTestFlag>LIVE</npx:liveTestFlag>
      <npx:filer>
        <npx:issuerCredentials>
          <npx:cik>0001443689</npx:cik>
          <npx:ccc>XXXXXXXX</npx:ccc>
        </npx:issuerCredentials>
      </npx:filer>
      <npx:periodOfReport>06/30/2026</npx:periodOfReport>
    </npx:filerInfo>
  </npx:headerData>
  <npx:formData>
    <npx:coverPage>
      <npx:yearOrQuarter>YEAR</npx:yearOrQuarter>
      <npx:reportCalendarYear>2026</npx:reportCalendarYear>
      <npx:reportingPerson>
        <npx:name>Senator Investment Group LP</npx:name>
        <npx:phoneNumber>212-376-4300</npx:phoneNumber>
        <npx:address>
          <common:street1>124 East 14th Street</common:street1>
          <common:street2>20th Floor</common:street2>
          <common:city>New York</common:city>
          <common:stateOrCountry>NY</common:stateOrCountry>
          <common:zipCode>10003</common:zipCode>
        </npx:address>
      </npx:reportingPerson>
      <npx:agentForService>
        <npx:name>Edward Larmann</npx:name>
        <npx:address>
          <common:street1>124 East 14th Street</common:street1>
          <common:street2>20th Floor</common:street2>
          <common:city>New York</common:city>
          <common:stateOrCountry>NY</common:stateOrCountry>
          <common:zipCode>10003</common:zipCode>
        </npx:address>
      </npx:agentForService>
      <npx:reportInfo>
        <npx:reportType>INSTITUTIONAL MANAGER VOTING REPORT</npx:reportType>
      </npx:reportInfo>
      <npx:fileNumber>028-13389</npx:fileNumber>
      <npx:reportingCrdNumber>160935</npx:reportingCrdNumber>
      <npx:reportingSecFileNumber>801-73289</npx:reportingSecFileNumber>
      <npx:leiNumber>1CREOOR0KBP7SJQVGU28</npx:leiNumber>
      <npx:explanatoryInformation>
        <npx:explanatoryChoice>N</npx:explanatoryChoice>
      </npx:explanatoryInformation>
    </npx:coverPage>
    <npx:summaryPage>
      <npx:otherIncludedManagersCount>0</npx:otherIncludedManagersCount>
    </npx:summaryPage>
    <npx:signaturePage>
      <npx:reportingPerson>Senator Investment Group LP</npx:reportingPerson>
      <npx:txSignature>Edward Larmann</npx:txSignature>
      <npx:txPrintedSignature>Edward Larmann</npx:txPrintedSignature>
      <npx:txTitle>COO</npx:txTitle>
      <npx:txAsOfDate>08/17/2026</npx:txAsOfDate>
    </npx:signaturePage>
  </npx:formData>
</npx:edgarSubmission>
