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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2013-07-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001566897</issuerCik>
        <issuerName>Diamond Resorts International, Inc.</issuerName>
        <issuerTradingSymbol>DRII</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001283072</rptOwnerCik>
            <rptOwnerName>GUGGENHEIM CAPITAL LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 WEST MONROE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4900</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</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>0001425498</rptOwnerCik>
            <rptOwnerName>Guggenheim Partners, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>135 EAST 57TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</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>0001581086</rptOwnerCik>
            <rptOwnerName>Guggenheim Partners Investment Management Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>227 W MONROE ST</rptOwnerStreet1>
            <rptOwnerStreet2>STE 4800</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</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>0001425852</rptOwnerCik>
            <rptOwnerName>Guggenheim Partners Investment Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 WILSHIRE BOULEVARD, &amp;NBSP5TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA MONICA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90401</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.01 par value per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11338566</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Call Option (obligation to sell)</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.63</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-07-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, $0.01 par value per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4510774</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This amount represents shares of common stock, par value $0.01 per share, (&quot;Common Stock&quot;) of Diamond Resorts International, Inc. (the &quot;Issuer&quot;) being issued immediately prior to the closing of the initial public offering of the Common Stock in exchange for units of Diamond Resorts Parent, LLC.</footnote>
        <footnote id="F2">These shares of Common Stock are held directly by DRP Holdco, LLC. These shares of Common Stock may be deemed to be beneficially owned by the following, each of whom is a Reporting Person: Guggenheim Partners Investment Management, LLC (&quot;GPIM&quot;), which, via its relationship with the managing members of DRP Holdco, LLC, whose unanimous consent is required for decisions regarding assets held by DRP Holdco, LLC and who have granted full investment discretion and voting authority to GPIM over their units in DRP Holdco, LLC, exercises complete voting and dispositive power over the shares of Common Stock held by DRP Holdco, LLC; Guggenheim Partners Investment Management Holdings, LLC (&quot;GPIMH&quot;), as sole owner of GPIM; Guggenheim Partners, LLC, as sole owner of GPIMH; and Guggenheim Capital, LLC, as the majority owner of Guggenheim Partners, LLC.</footnote>
        <footnote id="F3">DRP Holdco, LLC has entered into a Stockholders Agreement, dated July 17, 2013, with other individuals and entities becoming stockholders of the Issuer.  Pursuant to the Stockholders Agreement, each of the parties thereto has agreed to cause the shares of Common Stock held by such party to be voted, at any meeting of stockholders called for such purpose, for the individuals nominated by the Issuer's board of directors for election to the Issuer's board of directors.  As a result of the Stockholders Agreement, the parties thereto constitute a &quot;group&quot; (as such term is defined in Section 13(d)(3) of the Securities Exchange Act, as amended (&quot;Exchange Act&quot;), and Rule 13d-5 promulgated thereunder).</footnote>
        <footnote id="F4">Each of the reporting persons disclaims beneficial ownership of the shares of Common Stock held by members of such group, except to the extent of such reporting person's pecuniary interest therein, and this statement shall not be construed as an admission that such reporting person is the beneficial owner of any such shares for purposes of Section 16 of the Exchange Act or for any other purpose.</footnote>
        <footnote id="F5">This represents Common Stock which 1818 Partners, LLC may acquire from DRP Holdco, LLC pursuant to a fully exercisable call option, dated as of July 21, 2011.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Guggenheim Capital, LLC, By: Robert Saperstein, Managing Director, /s/ Robert Saperstein</signatureName>
        <signatureDate>2013-07-18</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Guggenheim Partners, LLC, By:  Guggenheim Capital, LLC, parent company, By:  Robert Saperstein, Managing Director, /s/ Robert Saperstein</signatureName>
        <signatureDate>2013-07-18</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Guggenheim Partners Investment Management Holdings, LLC, By:  Guggenheim Capital, LLC, parent company, By:  Robert Saperstein, Managing Director, /s/ Robert Saperstein</signatureName>
        <signatureDate>2013-07-18</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Guggenheim Partners Investment Management, LLC, By: Guggenheim Capital, LLC, parent company, By:  Robert Saperstein, Managing Director, /s/ Robert Saperstein</signatureName>
        <signatureDate>2013-07-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
