Report of Foreign Issuer (6-k)

FORM 6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Report of Foreign Private Issuer

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

the Securities Exchange Act of 1934

For the month of December 2016

Commission File Number: 001-34848

SEANERGY MARITIME HOLDINGS CORP.

(Translation of registrant's name into English)

16 Grigoriou Lambraki Street

166 74 Glyfada

Athens, Greece

(Address of principal executive office)

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

Form 20-F [X] 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): ___

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

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: ___

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant's "home country"), or under the rules of the home country exchange on which the registrant's securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant's security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

On December 21, 2016, Seanergy Maritime Holdings Corp. (the "Company") completed the sale of an additional 1,300,000 of its common shares and class A warrants to purchase 1,500,000 common shares of the Company (the "Additional Securities") pursuant to the exercise of the over-allotment option granted to the underwriters in the Company's public offering that closed on December 13, 2016 (the "Offering"). In connection with the sale of Additional Securities, the Company issued the representative of the underwriters a warrant to purchase 65,000 of its common shares.

Attached to this report on Form 6-K as Exhibit 4.1 is a copy of the Representative's Warrant, dated December 21, 2016, issued to the representative of the underwriters in the Offering.

The information contained in this report on Form 6-K is hereby incorporated by reference into the Company's registration statement on Form F-3 (File No. 333-205301) filed with the U.S. Securities and Exchange Commission with an effective date of August 14, 2015.

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.