content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001553647</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001315257</issuerCik>
        <issuerName>Koppers Holdings Inc.</issuerName>
        <secFileNumber>001-32737</secFileNumber>
        <issuerAddress>
          <com:street1>436 SEVENTH AVENUE</com:street1>
          <com:city>PITTSBURGH</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>15219</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>412-227-2001</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Dowd Joseph P</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Fidelity Brokerage Services LLC</name>
          <address>
            <com:street1>900 Salem Street</com:street1>
            <com:city>Smithfield</com:city>
            <com:stateOrCountry>RI</com:stateOrCountry>
            <com:zipCode>02917</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>2600</noOfUnitsSold>
        <aggregateMarketValue>117867.04</aggregateMarketValue>
        <noOfUnitsOutstanding>20823066</noOfUnitsOutstanding>
        <approxSaleDate>12/14/2023</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/27/2018</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2600</amountOfSecuritiesAcquired>
        <paymentDate>03/27/2018</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Joseph Dowd</name>
          <address>
            <com:street1>436 Seventh Avenue</com:street1>
            <com:city>Pittsburgh</com:city>
            <com:stateOrCountry>PA</com:stateOrCountry>
            <com:zipCode>15219</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <saleDate>11/17/2023</saleDate>
        <amountOfSecuritiesSold>5250</amountOfSecuritiesSold>
        <grossProceeds>222907.65</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>12/14/2023</noticeDate>
        <signature>/s/ Daniel Tucci, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Joseph Dowd</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
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text: 144
  0001553647
  XXXXXXXX
  LIVE
  0001315257
  Koppers Holdings Inc.
  001-32737
  436 SEVENTH AVENUE
  PITTSBURGH
  PA
  15219
  412-227-2001
  Dowd Joseph P
  Officer
  Common
  Fidelity Brokerage Services LLC
  900 Salem Street
  Smithfield
  RI
  02917
  2600
  117867.04
  20823066
  12/14/2023
  NYSE
  Common
  03/27/2018
  Restricted Stock Vesting
  Issuer
  N
  2600
  03/27/2018
  Compensation
  N
  Joseph Dowd
  436 Seventh Avenue
  Pittsburgh
  PA
  15219
  Common
  11/17/2023
  5250
  222907.65
  12/14/2023
  /s/ Daniel Tucci, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Joseph Dowd