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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 QdRdmYv7Z5F2AbYZPQcrllVADI2AIK54u8ykbHX/EqVbo2KkoLDtali2DO1uxKBa
 +30uCBKoMXhjWsnukJcRjA==

<SEC-DOCUMENT>0001140361-06-001506.txt : 20060202
<SEC-HEADER>0001140361-06-001506.hdr.sgml : 20060202
<ACCEPTANCE-DATETIME>20060202151356
ACCESSION NUMBER:		0001140361-06-001506
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060131
FILED AS OF DATE:		20060202
DATE AS OF CHANGE:		20060202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hyde Leslie S
		CENTRAL INDEX KEY:			0001349675

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32737
		FILM NUMBER:		06573309

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		412-227-2889

	MAIL ADDRESS:	
		STREET 1:		C/O KOPPERS INC
		STREET 2:		436 SEVENTH AVENUE, SUITE 1550
		CITY:			PITTSBURG
		STATE:			PA
		ZIP:			15219

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Koppers Holdings Inc.
		CENTRAL INDEX KEY:			0001315257
		STANDARD INDUSTRIAL CLASSIFICATION:	LUMBER & WOOD PRODUCTS (NO FURNITURE) [2400]
		IRS NUMBER:				201878963
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		436 SEVENTH AVENUE
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15219
		BUSINESS PHONE:		412-227-2001

	MAIL ADDRESS:	
		STREET 1:		436 SEVENTH AVENUE
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15219

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KI Holdings Inc.
		DATE OF NAME CHANGE:	20050124
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001315257</issuerCik>
        <issuerName>Koppers Holdings Inc.</issuerName>
        <issuerTradingSymbol>KOP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001349675</rptOwnerCik>
            <rptOwnerName>Hyde Leslie S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>KOPPERS HOLDINGS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>436 SEVENTH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP Sfty Env.Aff.Koppers Inc.</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-01-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10950</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Steven R. Lacy, Attorney-in-Fact</signatureName>
        <signatureDate>2006-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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