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>6000</noOfUnitsSold>
        <aggregateMarketValue>266767.50</aggregateMarketValue>
        <noOfUnitsOutstanding>21200184</noOfUnitsOutstanding>
        <approxSaleDate>05/17/2024</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/17/2017</acquiredDate>
        <natureOfAcquisitionTransaction>LTI Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1</amountOfSecuritiesAcquired>
        <paymentDate>02/17/2017</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>09/28/2018</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>25</amountOfSecuritiesAcquired>
        <paymentDate>09/28/2018</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>12/03/2018</acquiredDate>
        <natureOfAcquisitionTransaction>LTI Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>583</amountOfSecuritiesAcquired>
        <paymentDate>12/03/2018</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/21/2019</acquiredDate>
        <natureOfAcquisitionTransaction>LTI Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1670</amountOfSecuritiesAcquired>
        <paymentDate>03/21/2019</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>06/28/2019</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>299</amountOfSecuritiesAcquired>
        <paymentDate>06/28/2019</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>09/30/2019</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>271</amountOfSecuritiesAcquired>
        <paymentDate>09/30/2019</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>12/31/2019</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>286</amountOfSecuritiesAcquired>
        <paymentDate>12/31/2019</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>02/28/2020</acquiredDate>
        <natureOfAcquisitionTransaction>LTI Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>488</amountOfSecuritiesAcquired>
        <paymentDate>02/28/2020</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/02/2020</acquiredDate>
        <natureOfAcquisitionTransaction>LTI Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>241</amountOfSecuritiesAcquired>
        <paymentDate>03/02/2020</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/31/2021</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>139</amountOfSecuritiesAcquired>
        <paymentDate>03/31/2021</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>06/30/2021</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>409</amountOfSecuritiesAcquired>
        <paymentDate>06/30/2021</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>09/30/2021</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>30</amountOfSecuritiesAcquired>
        <paymentDate>09/30/2021</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>12/31/2021</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>25</amountOfSecuritiesAcquired>
        <paymentDate>12/31/2021</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/31/2022</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>34</amountOfSecuritiesAcquired>
        <paymentDate>03/31/2022</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>06/30/2022</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>35</amountOfSecuritiesAcquired>
        <paymentDate>06/30/2022</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/03/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1059</amountOfSecuritiesAcquired>
        <paymentDate>03/03/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/06/2023</acquiredDate>
        <natureOfAcquisitionTransaction>Restricted Stock Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>372</amountOfSecuritiesAcquired>
        <paymentDate>03/06/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>03/31/2023</acquiredDate>
        <natureOfAcquisitionTransaction>ESPP Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>33</amountOfSecuritiesAcquired>
        <paymentDate>03/31/2023</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Joseph P. 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>03/01/2024</saleDate>
        <amountOfSecuritiesSold>14500</amountOfSecuritiesSold>
        <grossProceeds>774077.90</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Joseph P. 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>03/04/2024</saleDate>
        <amountOfSecuritiesSold>3488</amountOfSecuritiesSold>
        <grossProceeds>187014.78</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Joseph P. 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>03/05/2024</saleDate>
        <amountOfSecuritiesSold>13897</amountOfSecuritiesSold>
        <grossProceeds>743517.23</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Joseph P. 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>03/06/2024</saleDate>
        <amountOfSecuritiesSold>1300</amountOfSecuritiesSold>
        <grossProceeds>68016.48</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>05/17/2024</noticeDate>
        <signature>/s/ Ryan Riviere, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Joseph P. Dowd</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 14004}]
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
  6000
  266767.50
  21200184
  05/17/2024
  NYSE
  Common
  02/17/2017
  LTI Plan
  Issuer
  N
  1
  02/17/2017
  Compensation
  Common
  09/28/2018
  ESPP Purchase
  Issuer
  N
  25
  09/28/2018
  Cash
  Common
  12/03/2018
  LTI Plan
  Issuer
  N
  583
  12/03/2018
  Compensation
  Common
  03/21/2019
  LTI Plan
  Issuer
  N
  1670
  03/21/2019
  Compensation
  Common
  06/28/2019
  ESPP Purchase
  Issuer
  N
  299
  06/28/2019
  Cash
  Common
  09/30/2019
  ESPP Purchase
  Issuer
  N
  271
  09/30/2019
  Cash
  Common
  12/31/2019
  ESPP Purchase
  Issuer
  N
  286
  12/31/2019
  Cash
  Common
  02/28/2020
  LTI Plan
  Issuer
  N
  488
  02/28/2020
  Compensation
  Common
  03/02/2020
  LTI Plan
  Issuer
  N
  241
  03/02/2020
  Compensation
  Common
  03/31/2021
  ESPP Purchase
  Issuer
  N
  139
  03/31/2021
  Cash
  Common
  06/30/2021
  ESPP Purchase
  Issuer
  N
  409
  06/30/2021
  Cash
  Common
  09/30/2021
  ESPP Purchase
  Issuer
  N
  30
  09/30/2021
  Cash
  Common
  12/31/2021
  ESPP Purchase
  Issuer
  N
  25
  12/31/2021
  Cash
  Common
  03/31/2022
  ESPP Purchase
  Issuer
  N
  34
  03/31/2022
  Cash
  Common
  06/30/2022
  ESPP Purchase
  Issuer
  N
  35
  06/30/2022
  Cash
  Common
  03/03/2023
  Restricted Stock Vesting
  Issuer
  N
  1059
  03/03/2023
  Compensation
  Common
  03/06/2023
  Restricted Stock Vesting
  Issuer
  N
  372
  03/06/2023
  Compensation
  Common
  03/31/2023
  ESPP Purchase
  Issuer
  N
  33
  03/31/2023
  Cash
  N
  Joseph P. Dowd
  436 Seventh Avenue
  Pittsburgh
  PA
  15219
  Common
  03/01/2024
  14500
  774077.90
  Joseph P. Dowd
  436 Seventh Avenue
  Pittsburgh
  PA
  15219
  Common
  03/04/2024
  3488
  187014.78
  Joseph P. Dowd
  436 Seventh Avenue
  Pittsburgh
  PA
  15219
  Common
  03/05/2024
  13897
  743517.23
  Joseph P. Dowd
  436 Seventh Avenue
  Pittsburgh
  PA
  15219
  Common
  03/06/2024
  1300
  68016.48
  05/17/2024
  /s/ Ryan Riviere, as a duly authorized representative of Fidelity Brokerage Services LLC, as attorney-in-fact for Joseph P. Dowd