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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-18</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000750199</issuerCik>
        <issuerName>ENERGY PARTNERS LTD</issuerName>
        <issuerTradingSymbol>EPL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001245638</rptOwnerCik>
            <rptOwnerName>DUHAMEL WILLIAM F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARALLON CAPITAL MANAGEMENT, L.L.C.,</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARITIME PLAZA, SUITE 2100</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of Group Owning 10%</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001348541</rptOwnerCik>
            <rptOwnerName>Moment Jason E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARALLON CAPITAL MANAGEMENT, L.L.C.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARITIME PLAZA, SUITE 2100</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of Group Owning 10%</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001405852</rptOwnerCik>
            <rptOwnerName>Pant Ashish H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARALLON CAPITAL MANAGEMENT, L.L.C.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARITIME PLAZA, SUITE 2100</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of Group Owning 10%</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001453076</rptOwnerCik>
            <rptOwnerName>Voon Richard H.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FARALLON CAPITAL MANAGEMENT, L.L.C.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARITIME PLAZA, SUITE 2100</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Member of Group Owning 10%</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Each of William F. Duhamel, Jason E. Moment, Ashish H. Pant and Richard H. Voon previously filed Form 3s and Form 4s  with respect to securities of the Issuer owned directly by (a) Farallon Capital Partners, L.P., Farallon Capital Institutional Partners, L.P., Farallon Capital Institutional Partners II, L.P. and Farallon Capital Offshore Investors II, L.P. (collectively, the &quot;Partnerships&quot;), (b) Saddle Rock Onshore Funding, L.L.C. (the &quot;SPV&quot;) managed by Lighthouse Hill Capital Management II, L.L.C. (the &quot;SPV Manager&quot;) and (c) one or more discretionary accounts (the &quot;Managed Accounts&quot;) managed by Farallon Capital Management, L.L.C (&quot;FCMLLC&quot;).</footnote>
        <footnote id="F2">As a managing member of Farallon Partners, L.L.C. (&quot;FPLLC&quot;), the general partner of each of the Partnerships, and FCMLLC, the registered investment advisor to the SPV, the SPV Manager and the Managed Accounts, each of Messrs. Duhamel, Moment, Pant and Voon may have been deemed a beneficial owner of the Issuer's securities deemed beneficially owned by FPLLC and FCMLLC.  Effective as of March 18, 2010, in connection with their respective resignations as managing members of FPLCC and FCMLLC, each of Messrs. Duhamel, Moment, Pant and Voon may no longer be deemed a beneficial owner of any of the Issuer's securities deemed beneficially owned by FPLLC and FCMLLC.</footnote>
        <footnote id="F3">Each of Messrs. Duhamel, Moment, Pant and Voon, FCMLLC, the SPV Manager and the other individuals identified in the prior Form 3s and Form 4s filed by the foregoing disclaims any beneficial ownership of any of the Issuer's securities reported or referred to herein or therein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the &quot;'34 Act&quot;), or otherwise, except to the extent of its, his or her pecuniary interest, if any. FPLLC disclaims any beneficial ownership of any of the Issuer's securities reported or referred to herein or in such prior Form 3s and Form 4s for purposes of Section 16 of the '34 Act or otherwise, except as to securities representing FPLLC's pro rata interest in, and interest in the profits of, the Partnerships.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Monica R. Landry, as attorney-in-fact for William F. Duhamel, Jason E. Moment, Ashish H. Pant and Richard H. Voon</signatureName>
        <signatureDate>2010-03-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>.</signatureName>
        <signatureDate>2010-03-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>.</signatureName>
        <signatureDate>2010-03-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>.</signatureName>
        <signatureDate>2010-03-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
