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

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of August 2024

Commission File Number 001-41717

C3IS INC.

(Translation of registrant’s name into English)

331 Kifissias Avenue Erithrea 14561 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 ☒   Form 40-F ☐

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

Financial and Operating Results for the three and six months ended June 30, 2024

Attached to this report on Form 6-K as Exhibit 99.1 is a copy of C3is Inc.’s press release, dated August 22, 2024, announcing financial and operating results for the three and six months ended June 30, 2024.

EXHIBIT INDEX

99.1 C3is Inc. press release, dated August 22, 2024, announcing financial and operating results for the three and six months ended June 30, 2024

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.

Date: August 23, 2024

C3IS INC.
By:	/s/ Nina Pyndiah
Name:	Nina Pyndiah
Title:	Chief Financial Officer