Report of Foreign Issuer (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

of the Securities Exchange Act of 1934

Date of report: July 27, 2017

Commission file number 1-33198

TEEKAY OFFSHORE PARTNERS L.P.

(Exact name of Registrant as specified in its charter)

4th Floor

Belvedere Building

69 Pitts Bay Road

Hamilton, HM08 Bermuda

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F ☒ Form 40- F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1).

Yes ☐ No ☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7).

Yes ☐ No ☒

Item 1- Information Contained in this Report on Form 6-K

Attached as Exhibit 99.1 is a copy of an announcement of Teekay Offshore Partners L.P. dated July 26, 2017.

Attached as Exhibit 99.2 is a copy of a presentation used by Teekay Offshore Partners L.P. on July 27, 2017 in connection with an investor call relating to the transactions described in the announcement attached to this Report as Exhibit 99.1.

SIGNATURES

Pursuant to the requirements 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.