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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-11-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001041657</issuerCik>
        <issuerName>URBAN ONE, INC.</issuerName>
        <issuerTradingSymbol>UONE/UONEK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001221506</rptOwnerCik>
            <rptOwnerName>LIGGINS ALFRED C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class D Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>249541</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.21</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14693156</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class D Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>287231</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.26</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14980387</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class D Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>182371</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.32</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15162758</value>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. The shares were bought in multiple transactions at prices ranging from $1.16 to $1.24, inclusive. The reporting person undertakes to provide to Urban One, Inc., any security holder of Urban One, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. The shares were bought in multiple transactions at prices ranging from $1.21 to $1.31, inclusive. The reporting person undertakes to provide to Urban One, Inc., any security holder of Urban One, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. The shares were bought in multiple transactions at prices ranging from $1.25 to $1.39, inclusive. The reporting person undertakes to provide to Urban One, Inc., any security holder of Urban One, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.</footnote>
        <footnote id="F4">The total represents all shares held by the reporting person across all classes of Urban One, Inc. stock, Classes A, B, C, and D.  The reporting person beneficially owns a total of Urban One, Inc. stock as follows: (1) 2,010,307 shares of Class B common stock held by the Alfred C. Liggins Revocable Trust; (2) 605,313 shares of Class C common stock held by the Alfred C. Liggins Revocable Trust U/A/D; (3) 920,456 shares of Class C common stock held by the Dynastic Trust U/A/D; (4) 15,605 shares of Class C common stock held by the Hughes-Liggins Co., LLC; (5) 2,812,671 shares of Class D common stock held by Alfred C. Liggins; (6) 3,896,734 shares of Class D common stock held by the Alfred C. Liggins Revocable Trust; (7) 3,012,237 shares of Class D common stock held by the Alfred C. Liggins Revocable Trust U/A/D; (8) 1,519,128 shares of Class D common stock held by the Alfred C. Liggins Revocable Trust UA; (cont.)</footnote>
        <footnote id="F5">(9) 338,808 shares of Class D common stock held by the Dynastic Trust U/A/D; and (10) 31,499 shares of Class D common stock held by the Hughes-Liggins Co., LLC.  More information on Mr. Liggins' ownership is included in our most recent proxy filed on April 29, 2020.</footnote>
        <footnote id="F6">This total excludes the number of stock options held.  More information on Mr. Liggins' ownership is included in our most recent proxy filed on April 29, 2020.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Karen Wishart</signatureName>
        <signatureDate>2020-11-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
