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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-03-06</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001223389</issuerCik>
        <issuerName>CONNS INC</issuerName>
        <issuerTradingSymbol>CONN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300714</rptOwnerCik>
            <rptOwnerName>Anchorage Capital Group, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>610 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</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>0001300711</rptOwnerCik>
            <rptOwnerName>Anchorage Advisors Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>610 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300650</rptOwnerCik>
            <rptOwnerName>Davis Anthony Lynn</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>610 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300710</rptOwnerCik>
            <rptOwnerName>Ulrich Kevin Michael</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>610 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300713</rptOwnerCik>
            <rptOwnerName>Anchorage Capital Master Offshore, Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>610 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>303000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.8451</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4241257</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1900</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.9445</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4243157</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>39516</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.147</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4203641</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>202984</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.2985</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000657</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>177283</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.1907</value>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3823374</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, $0.01 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-10</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>202717</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.3128</value>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3620657</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F7"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Anchorage Capital Master Offshore, Ltd.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This price reflects the weighted average price for open-market purchases of shares of Common Stock made by the Reporting Persons on March 6, 2015, within a $1.00 range. The actual prices for these transactions range from $27.465 to $28.00, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock purchased at each separate price.</footnote>
        <footnote id="F2">This price reflects the weighted average price for open-market purchases of shares of Common Stock made by the Reporting Persons on March 9, 2015, within a $1.00 range. The actual prices for these transactions range from $27.90 to $28.02, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock purchased at each separate price.</footnote>
        <footnote id="F3">This price reflects the weighted average price for open-market sales of shares of Common Stock made by the Reporting Persons on March 9, 2015, within a $1.00 range. The actual prices for these transactions range from $27.00 to $27.30, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock sold at each separate price.</footnote>
        <footnote id="F4">This price reflects the weighted average price for open-market sales of shares of Common Stock made by the Reporting Persons on March 9, 2015, within a $1.00 range. The actual prices for these transactions range from $26.00 to $26.83, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock sold at each separate price.</footnote>
        <footnote id="F5">This price reflects the weighted average price for open-market sales of shares of Common Stock made by the Reporting Persons on March 10, 2015, within a $1.00 range. The actual prices for these transactions range from $24.93 to $25.74, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock sold at each separate price.</footnote>
        <footnote id="F6">This price reflects the weighted average price for open-market sales of shares of Common Stock made by the Reporting Persons on March 10, 2015, within a $1.00 range. The actual prices for these transactions range from $23.91 to $24.90, inclusive. The Reporting Persons further undertake to provide upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares of Common Stock sold at each separate price.</footnote>
        <footnote id="F7">Anchorage Advisors Management, L.L.C. is the sole managing member of Anchorage Capital Group, L.L.C., the investment advisor to Anchorage Capital Master Offshore, Ltd.  Mr. Davis is the President of Anchorage Capital Group, L.L.C. and a managing member of Anchorage Advisors Management, L.L.C. Mr. Ulrich is the Chief Executive Officer of Anchorage Capital Group, L.L.C. and the other managing member of Anchorage Advisors Management, L.L.C.</footnote>
        <footnote id="F8">Each reporting person disclaims beneficial ownership of the reported securities except to the extent, if any, of its or his pecuniary interest therein, and this report shall not be deemed an admission that such reporting person is the beneficial owner of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Anchorage Capital Group, L.L.C., By: /s/ Kevin M. Ulrich, Authorized Signatory</signatureName>
        <signatureDate>2015-03-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Anchorage Advisors Management, L.L.C., By: /s/ Kevin M. Ulrich, Authorized Signatory</signatureName>
        <signatureDate>2015-03-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Anthony L. Davis</signatureName>
        <signatureDate>2015-03-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Kevin M. Ulrich</signatureName>
        <signatureDate>2015-03-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Anchorage Capital Master Offshore, Ltd., By: /s/ Natalie Birrell, Director</signatureName>
        <signatureDate>2015-03-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
