<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-05-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001632933</issuerCik>
        <issuerName>EQT GP Holdings, LP</issuerName>
        <issuerTradingSymbol>EQGP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000033213</rptOwnerCik>
            <rptOwnerName>EQT Corp</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>625 LIBERTY AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1700</rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001607404</rptOwnerCik>
            <rptOwnerName>EQT Gathering Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>625 LIBERTY AVENUE, SUITE 1700</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001607430</rptOwnerCik>
            <rptOwnerName>EQT Production Co</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>625 LIBERTY AVENUE, SUITE 1700</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001552977</rptOwnerCik>
            <rptOwnerName>EQT Investments Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>101 CONVENTION CENTER DRIVE, SUITE 850</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Units</value>
            </securityTitle>
            <transactionDate>
                <value>2015-05-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>266165000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>266165000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>FN</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Units</value>
            </securityTitle>
            <transactionDate>
                <value>2015-05-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>26450000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>239715000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>FN</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to a recapitalization in connection with the initial public offering of the Issuer's common units, 99.9% of the outstanding limited partner interests of the Issuer were converted into 265,899,000 common units of the Issuer held by EQT Gathering Holdings, LLC (Gathering Holdings), and the remaining 0.1% of the outstanding limited partner interests of the Issuer were converted into 266,000 common units of the Issuer held by EQT GP Corporation.</footnote>
        <footnote id="F2">This Form 4 is being filed jointly by EQT Corporation (EQT), EQT Investments Holdings, LLC (Investments Holdings), EQT Production Company (EQT Production) and Gathering Holdings. The common units of the Issuer are owned directly by Gathering Holdings and EQT GP Corporation.  Gathering Holdings is the sole stockholder of EQT GP Corporation.  EQT Production directly owns 100% of the outstanding membership interests of Gathering Holdings.  Investments Holdings is the sole stockholder of EQT Production.  EQT directly owns 100% of the outstanding membership interests of Investments Holdings.  EQT, Investments Holdings, EQT Production and Gathering Holdings may therefore be deemed to beneficially own securities of the Issuer owned directly by EQT GP Corporation and Gathering Holdings.</footnote>
        <footnote id="F3">On May 15, 2015, Gathering Holdings sold 26,450,000 common units of the Issuer to the public in connection with the initial public offering of the Issuer at a price of $27.00 per common unit.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Randall L. Crawford, President of EQT Gathering Holdings, LLC</signatureName>
        <signatureDate>2015-05-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Steven T. Schlotterbeck, President of EQT Production Company</signatureName>
        <signatureDate>2015-05-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Joshua C. Miller, Vice President of EQT Investments Holdings, LLC</signatureName>
        <signatureDate>2015-05-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Philip P. Conti, Senior Vice President &amp; Chief Financial Officer of EQT Corporation</signatureName>
        <signatureDate>2015-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
