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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-01-20</periodOfReport>

    <issuer>
        <issuerCik>0000888491</issuerCik>
        <issuerName>OMEGA HEALTHCARE INVESTORS INC</issuerName>
        <issuerTradingSymbol>OHI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001157251</rptOwnerCik>
            <rptOwnerName>STEPHENSON ROBERT O</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>303 INTERNATIONAL CIRCLE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>HUNT VALLEY</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Profit Interest Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-01-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20342</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>OP Units</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20342</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>163529</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents grant of Profits Interest Units (&quot;Profits Units&quot;) in OHI Healthcare Properties Limited Partnership (the &quot;Operating Partnership&quot;), of which the Issuer is the general partner.  Each Profits Unit represents a contingent right to receive one unit of limited partnership interest (an &quot;OP Unit&quot;) in the Operating Partnership upon vesting and the satisfaction of certain tax-driven economic requirements. Each OP Unit is redeemable at the election of the holder for cash equal to the then fair market value of one share of Issuer common stock, or at the Issuer's election, one share of  Issuer common stock, subject to adjustment as set forth in the partnership agreement.</footnote>
        <footnote id="F2">Subject to three-year cliff vesting on 12/31/2023 and subject to continued employment on the vesting date with certain exceptions for qualifying termination of employment. OP Units do not expire.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Thomas H. Peterson, Attorney-in-Fact</signatureName>
        <signatureDate>2021-01-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
