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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-12-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001620280</issuerCik>
        <issuerName>Uniti Group Inc.</issuerName>
        <issuerTradingSymbol>UNIT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001616039</rptOwnerCik>
            <rptOwnerName>Gunderman Kenny</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10802 EXECUTIVE CENTER DR</rptOwnerStreet1>
            <rptOwnerStreet2>BENTON BUILDING, SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>LITTLE ROCK</rptOwnerCity>
            <rptOwnerState>AR</rptOwnerState>
            <rptOwnerZipCode>72211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>79187</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>636425</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">In 2019, the issuer's compensation committee approved a one-time bonus opportunity for the issuer's executive officers, payable, if at all, in the committee's discretion following the emergence of Windstream Holdings, Inc. from bankruptcy. In the fourth quarter of 2020, the compensation committee approved bonus payouts equal to 75% of each officer's target cash incentive opportunity in effect in 2019, payable at the officer's election in either cash or time-based restricted stock subject to three-year vesting. The reporting person elected to receive his award in shares as reported herein. Subject to the reporting person's continued employment, these shares will vest in three equal installments on December 9 of each year, with the first vesting date being December 9, 2021.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kenny Gunderman by Daniel L. Heard, Attorney-In-Fact</signatureName>
        <signatureDate>2020-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
