[6-K] Okeanis Eco Tankers Corp. Current Report (Foreign Issuer)

Rhea-AI Filing Summary

Okeanis Eco Tankers Corp. filed a Form 6-K furnishing a press release inviting participants to its Q3 2025 results webcast.

The report and Exhibit 99.1 are incorporated by reference into the company’s Form F-3 registration statements (File Nos. 333-287032 and 333-287036), which were declared effective on May 21, 2025. The filing is signed by the Chief Financial Officer, Iraklis Sbarounis, and dated November 7, 2025.

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 November 2025

Commission File Number: 001-41858

Okeanis Eco Tankers Corp.

(Translation of registrant’s name into English)

c/o OET Chartering Inc., Ethnarchou Makariou Ave., & 2 D. Falireos St., 185 47 N. Faliro, 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 ¨

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

Attached to this report on Form 6-K as Exhibit 99.1 is a copy of the press release published by Okeanis Eco Tankers Corp. (the “Company”) on November 7, 2025, titled “ Okeanis Eco Tankers Corp. – Invitation to Q3 2025 Results Webcast.”

This Report and the exhibit(s) hereto are hereby incorporated by reference into the registrant’s registration statements: (A) on Form F-3 (File No. 333-287032), filed with the Securities and Exchange Commission on May 7, 2025 and declared effective on May 21, 2025 and (B) on Form F-3 (File No. 333-287036), filed with the Securities and Exchange Commission on May 7, 2025 and declared effective on May 21, 2025.

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.

Okeanis Eco Tankers Corp.

	By:	/s/ Iraklis Sbarounis
	Name:	Iraklis Sbarounis
	Title:	Chief Financial Officer

Date: November 7, 2025

FAQ

What did Okeanis Eco Tankers (ECO) file?

The company filed a Form 6-K furnishing a press release inviting participants to its Q3 2025 results webcast.

What is included with the 6-K?

It includes Exhibit 99.1, a press release titled “Okeanis Eco Tankers Corp. – Invitation to Q3 2025 Results Webcast.”

How does this 6-K relate to existing registrations?

The report and exhibit are incorporated by reference into the company’s Form F-3 registration statements.

What are the relevant F-3 file numbers and dates?

File Nos. 333-287032 and 333-287036, filed May 7, 2025 and declared effective May 21, 2025.

Who signed the filing and when?

The filing was signed by Iraklis Sbarounis, Chief Financial Officer, and dated November 7, 2025.