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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2013-02-28</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000826773</issuerCik>
        <issuerName>UniTek Global Services, Inc.</issuerName>
        <issuerTradingSymbol>UNTK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001569891</rptOwnerCik>
            <rptOwnerName>Unitek Interposed LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HMK GP LP</rptOwnerStreet1>
            <rptOwnerStreet2>200 CRESCENT COURT, SUITE 1600</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001569892</rptOwnerCik>
            <rptOwnerName>HMK GP LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CRESCENT COURT</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1600</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001569893</rptOwnerCik>
            <rptOwnerName>HMK GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HMK GP LP</rptOwnerStreet1>
            <rptOwnerStreet2>200 CRESCENT COURT, SUITE 1600</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4686196</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On February 28, 2013, UniTek Interposed LP (&quot;UniTek Interposed&quot;) completed a series of related transactions with Sector Performance Fund, LP, SPF SBS LP, HM Unitek Coinvest, LP and certain of their limited partners, pursuant to which, among other transactions, each of them transferred to UniTek Interposed all of their respective shares of Common Stock held of record in exchange for, through a series of transactions, either (i) an allocable portion of non-voting limited partner interests in UniTek Interposed or (ii) cash.</footnote>
        <footnote id="F2">Directly owned by UniTek Interposed LP.</footnote>
        <footnote id="F3">HMK GP LP (&quot;HMK GP&quot;) is the sole general partner and a limited partner of UniTek Interposed and, as a result thereof, HMK GP may be deemed to share beneficial ownership with respect to these securities.  HMK GP LLC (&quot;HMK LLC&quot;) is the sole general partner of HMK GP and, as a result thereof, HMK LLC may be deemed to share beneficial ownership with respect to these securities.  Except to the extent of any pecuniary interests therein, each of HMK GP and HMK LLC expressly disclaims the existence of such beneficial ownership.</footnote>
    </footnotes>

    <remarks>UNITEK INTERPOSED LP
By: HMK GP LP, its general partner
By: HMK GP LLC, its general partner

By:	/s/ David W. Knickel
Name:  David W. Knickel
Title: Vice President &amp; Chief Finanacial Officer



Exhibit 99.1 - Joint Filer Information, filed herewith and incorporated by reference herein.</remarks>

    <ownerSignature>
        <signatureName>See Remarks.</signatureName>
        <signatureDate>2013-03-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
