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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-08-22</periodOfReport>

    <issuer>
        <issuerCik>0000789570</issuerCik>
        <issuerName>MGM Resorts International</issuerName>
        <issuerTradingSymbol>MGM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001084356</rptOwnerCik>
            <rptOwnerName>SALEM PAUL J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3600 LAS VEGAS BLVD. SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89109</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-08-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3902</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock $.01 Par Value ND</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3902</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3902</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock Units (&quot;RSUs&quot;) granted under the MGM Resorts International Amended and Restated 2005 Omnibus Incentive Plan (the &quot;Plan&quot;). Each RSU represents the right to receive, following vesting, one share of MGM Resorts common stock.</footnote>
        <footnote id="F2">The RSUs will vest upon the earlier of (i) August 22, 2019 or (ii) the date of the Company's next annual meeting of stockholders, in each case subject to the terms of the Plan and applicable award agreement. Any fractional shares will be paid in cash upon settlement.</footnote>
        <footnote id="F3">RSUs do not have an expiration date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Andrew Hagopian III, Attorney-In-Fact</signatureName>
        <signatureDate>2018-08-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
