<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2010-04-08</periodOfReport>    <notSubjectToSection16>0</notSubjectToSection16>    <issuer>        <issuerCik>0000748790</issuerCik>        <issuerName>Global Clean Energy Holdings, Inc.</issuerName>        <issuerTradingSymbol>GCEH.OB</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001257936</rptOwnerCik>            <rptOwnerName>NELSON BRUCE K</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>6033 W. CENTURY BLVD., SUITE 895</rptOwnerStreet1>            <rptOwnerStreet2></rptOwnerStreet2>            <rptOwnerCity>LOS ANGELES</rptOwnerCity>            <rptOwnerState>CA</rptOwnerState>            <rptOwnerZipCode>90045</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isDirector>0</isDirector>            <isOfficer>1</isOfficer>            <isTenPercentOwner>0</isTenPercentOwner>            <isOther>0</isOther>            <officerTitle>Chief Financial Officer</officerTitle>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-04-08</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>P</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>1043000</value>                </transactionShares>                <transactionPricePerShare>                    <footnoteId id="F1"/>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>A</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>1043000</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>    </nonDerivativeTable>    <footnotes>        <footnote id="F1">On April 8, 2010, the Reporting Person purchased 1,043,000 shares of the Issuer's common stock at a per share price of $0.01.</footnote>    </footnotes>    <ownerSignature>        <signatureName>/s/ BRUCE NELSON</signatureName>        <signatureDate>2010-04-08</signatureDate>    </ownerSignature></ownershipDocument>