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

    <schemaVersion>X0205</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2012-04-26</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001455650</issuerCik>
        <issuerName>NorthStar Real Estate Income Trust, Inc.</issuerName>
        <issuerTradingSymbol>NONE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001497785</rptOwnerCik>
            <rptOwnerName>Smith Jack Fleming Jr.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTHSTAR REAL ESTATE INCOME TRUST</rptOwnerStreet1>
            <rptOwnerStreet2>399 PARK AVENUE, 18TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Restricted Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Restricted Common Stock</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to the NorthStar Real Estate Income Trust, Inc. (the &quot;Company&quot;) Independent Directors Compensation Plan (as amended, the &quot;Compensation Plan&quot;), at the commencement of the Company's initial public offering, each of the Company's independent directors received a grant of 5,000 shares of restricted common stock of the Company, par value $0.01 per share (the &quot;Restricted Stock&quot;).  These shares of Restricted Stock were issued on July 19, 2010 and vest quarterly over a four year period with an initial vesting date of October 1, 2010.  Restricted Stock has no expiration date.</footnote>
        <footnote id="F2">Pursuant to the Company's Compensation Plan, each independent director receives a grant of 2,500 shares of Restricted Stock following re-election to the Company's Board of Directors.  These shares of Restricted Stock were issued on June 7, 2011 and vest quarterly over a four year period with an intial vesting date of July 1, 2011.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Ronald J. Lieberman, as Attorney-in-Fact for Jack F. Smith, Jr.</signatureName>
        <signatureDate>2012-04-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
