UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM10-K

(Mark One)

For the fiscal year ended December 31, 2018.

or

For the transition period from                                                 to

Fifth Third Auto Trust2015-12017-1

(Exact name of issuing entity as specified in its charter)

Commission File Number of Issuing Entity:333-197420-02333-211395-01

Central Index Key Number of Issuing Entity: 00016528850001715585

Fifth Third Holdings Funding, LLC

(Exact name of depositor as specified in its charter)

Commission File Number of Depositor:333-197420333-211395

Central Index Key Number of Depositor: 0001405332

Fifth Third Bank

(Exact name of sponsor as specified in its charter)

Central Index Key Number of Sponsor: 0000035528

Delaware

(State or other jurisdiction of incorporation or organization of the issuing entity)

47-726347636-7706841

(I.R.S. Employer Identification No. of issuing entity)

c/o Fifth Third Holdings Funding, LLC

1701 Gold Road, Tower I, 9^th Floor

Rolling Meadows, Illinois

60008

(847)354-7341

(Address and telephone number of principal executive office of issuing entity)

Indicate by check mark if the registrant is a well-known seasoned issuer (as defined in Rule 405 of the Securities Act).    ☐  Yes    ☒   No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Securities Exchange Act.    ☐  Yes    ☒  No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     ☒  Yes    ☐  No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of RegulationsS-T (§ 232.405) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).    ☒  Yes    ☐  No

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of RegulationS-K (§ 229.405) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form10-K or any amendment to this Form10-K.    ☒

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.    ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Exchange Act).    ☐  Yes    ☒  No

State the aggregate market value of the voting andnon-voting common equity held bynon-affiliates computed by reference to the price at which the common equity was last sold, or the average bid and asked price of such common equity, as of the last business day of the registrant’s most recently completed second fiscal quarter.

Registrant does not have any voting ornon-voting common equity outstanding held bynon-affiliates, has not been involved in bankruptcy proceedings during the past five years and is not a corporate registrant.

Documents Incorporated by Reference.             See Exhibit Index.

PART I

THE FOLLOWING ITEMS HAVE BEEN OMITTED IN ACCORDANCE WITH GENERAL INSTRUCTION J TO FORMFORM 10-K:

Not applicable.

Not applicable.

PART II

THE FOLLOWING ITEMS HAVE BEEN OMITTED IN ACCORDANCE WITH GENERAL INSTRUCTION J TO FORM10-K:

PART III

THE FOLLOWING ITEMS HAVE BEEN OMITTED IN ACCORDANCE WITH GENERAL INSTRUCTION J TO FORMFORM 10-K:

PART IV

EXHIBIT INDEX

* Incorporated by reference.

Not applicable.

SUBSTITUTE INFORMATION PROVIDED IN ACCORDANCE WITH GENERAL INSTRUCTION J(2) TO FORM10-K:

Item 1112(b) of Regulation AB: Significant Obligors of Pool Assets (Financial information).

Not applicable.

Item 1114(b)(2) of Regulation AB: Credit Enhancement and Other Support, Except for Certain Derivatives Instruments (Financial information).

Not applicable.

Item 1115(b) of Regulation AB: Certain Derivatives Instruments (Financial information).

Not applicable.

Item 1117 of Regulation AB: Legal proceedings.

No legal proceedings are pending against any of Fifth Third Bank, an Ohio banking corporation (“Fifth Third”) (in its capacity as an originator contemplated by Item 1110(b) of Regulation AB (the “Originator”), in its capacity as sponsor (the “Sponsor”), in its capacity as servicer (the “Servicer”) and in its capacity as administrator (the “Administrator”) of Fifth Third Auto Trust2015-12017-1 (the “Issuing Entity”)), Fifth Third Holdings, LLC, as seller (the “Seller”), Fifth Third Holdings Funding, LLC (the “Depositor”), Wilmington Trust, National Association (the “Owner Trustee”), Deutsche Bank Trust Company Americas (the “Indenture Trustee”), the Issuing Entity, or of which any property of the foregoing is subject, that are material to holders of the asset-backed notes (the “Notes”) or asset-backed certificates (the “Certificates”), and no such proceedings are known to be contemplated by governmental authorities.

BNY Mellon Trust of Delaware, as the Delaware trustee (the “Delaware Trustee”), has provided the following information for inclusion in thisForm 10-K:

In the ordinary course of business, The Bank of New York Mellon, an affiliate of BNY Mellon Trust of Delaware, is named as a defendant in or made a party to pending and potential legal actions. In connection with its role as trustee of certain residential mortgage-backed securitization (“RMBS”) transactions, The Bank of New York Mellon has been named as defendant in a number of legal actions brought by RMBS investors. These lawsuits allege that the trustee had expansive duties under the governing agreements, including the duty to investigate and pursue breach of representation and warranty claims against other parties to the RMBS transactions. While it is inherently difficult to predict the eventual outcomes of pending actions, The Bank of New York Mellon denies liability and intends to defend the litigations vigorously.

Item 1119 of Regulation AB: Affiliations and Certain Relationships and Related Transactions.

The information required by Item 1119 of Regulation AB has been previously reported and has been omitted from this report on FormForm 10-K in reliance on the Instruction to Item 1119.

Item 1122 of Regulation AB: Compliance with Applicable Servicing Criteria.

Fifth Third and the Indenture Trustee (collectively, the “Servicing Parties”) have each been identified by the registrant as parties participating in the servicing function with respect to the asset pool held by the Issuing Entity. Each of the Servicing Parties has completed a report on an assessment of compliance with the servicing criteria set forth in paragraph (d) of Item 1122 of Regulation AB applicable to it (each, a “Servicing Assessment Report”), which Servicing Assessment Reports are attached as exhibits to this Form10-K. In addition, each of Fifth Third and the Indenture Trustee has provided an attestation report (each, an “Attestation Report”) by a registered public accounting firm, which reports are also attached as exhibits to this Form10-K. None of the Servicing Assessment Reports prepared by Fifth Third or the Indenture Trustee, and none of the related Attestation Reports, has identified any material instance of noncompliance with the servicing criteria applicable to the respective Servicing Party.

Item 1123 of Regulation AB: Servicer Compliance Statement.

Fifth Third has completed a statement of compliance with applicable servicing criteria (a “Compliance Statement”) signed by an authorized officer of Fifth Third and such Compliance Statement is attached as Exhibit 35.1 to this Form10-K.

Supplemental Information to be Furnished With Reports Filed Pursuant to Section 15(d) of the Act by Registrants Which Have Not Registered Securities Pursuant to Section 12 of the Act.

No annual report or proxy materials have been sent to security holders and no such report or proxy materials are to be furnished to security holders subsequent to the filing of this Annual Report on Form10-K.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: March 28, 2019