UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 4)*

trivago N.V.

(Name of Issuer)

Class A Shares, nominal value of €0.06 per share

(Title of Class of Securities)

89686D105 (for American Depositary Shares, each representing one Class A Share)

(CUSIP Number)

PAR Investment Partners, L.P.

200 Clarendon Street, 48^th Floor

Boston, MA 02116

Attn: Steven M. Smith

(617) 526-8990

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

February 8, 2021

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box:

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 89686D105

CUSIP No. 89686D105

CUSIP No. 89686D105

Introduction

This Amendment No. 4 to Schedule 13D amends Amendment No. 3 to Schedule 13D filed on February 1, 2021, which amended Amendment No. 2 to Schedule 13D filed on January 29, 2021, which amended Amendment No. 1 to Schedule 13 filed on June 13, 2019, which amended the Statement on Schedule 13D filed on September 18, 2018 (the “Schedule 13D”), and is being filed by PAR Investment Partners, L.P., a Delaware limited partnership (“PAR Investment Partners”), PAR Group II, L.P., a Delaware limited partnership (“PAR Group”), and PAR Capital Management, Inc., a Delaware corporation (“PAR Capital Management” and, together with PAR Investment Partners and PAR Group, the “Reporting Persons”), and relates to the Class A Shares, nominal value of €0.06 per share (the “Class A Shares”) of trivago N.V. (the “Issuer”). The Class A Shares reported herein are represented by an equal number of American Depositary Shares (“ADSs”) that are held directly by PAR Investment Partners, L.P.

Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Schedule 13D. The Schedule 13D is amended on a supplementary basis as follows; all items or responses not described herein, or exhibits not filed herewith, remain as previously reported in, or filed with, the Schedule 13D, as amended.

Item 5. INTEREST IN SECURITIES OF THE ISSUER

(c) Other than as described in the attached Annex I, there were no transactions by the Reporting Persons relating to the Class A Shares effected during the past sixty days.

Item 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER.

Item 6 is hereby amended and restated as follows

PAR Investment Partners holds a portion of its assets, which may include the Issuer’s securities, in prime brokerage accounts at various institutions, which accounts provide PAR Investment Partners with access to margin or other financing. The customer and related agreements governing such accounts generally provide the broker counterparty with security, collateral or similar rights of possession, sale or offset with respect to such account assets in the event of a customer default. Such agreements generally also provide the counterparty with rights to lend assets held in such account, in some cases without advance or other notification to the customer. To the extent the Issuer’s securities owned by PAR Investment Partners are held from time to time in such prime broker accounts, they may be subject to such counterparty rights.

Except as otherwise set forth in this report, there are no contracts, arrangements, understandings or relationships among the persons named in Item 2 or between such persons and any other person with respect to any securities of the Issuer.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

February 10, 2021

Annex I

Information With Respect to Transactions of Class A Shares during the Past 60 Days