ECO 6‑K: Q3 & nine‑month 2025 unaudited statements incorporated into F‑3

Rhea-AI Filing Summary

Okeanis Eco Tankers Corp. (ECO) furnished a Form 6‑K announcing the availability of its Unaudited Condensed Financial Statements for the third quarter and nine‑month period of 2025, provided via an attached press release dated November 12, 2025. The report and its exhibit are incorporated by reference into the company’s Form F‑3 registration statements (File Nos. 333‑287032 and 333‑287036), each declared effective on May 21, 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 12, 2025, titled “Okeanis Eco Tankers Corp. - Unaudited Condensed Financial Statements for the Third Quarter and Nine-Month Period of 2025.”

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 12, 2025

FAQ

What did Okeanis Eco Tankers (ECO) file?

A Form 6‑K furnishing a press release with Unaudited Condensed Financial Statements for Q3 and the nine‑month period of 2025.

What period does the ECO filing cover?

It covers the third quarter and nine‑month period of 2025.

How will this 6‑K be used in other filings?

The report and exhibit are incorporated by reference into ECO’s Form F‑3 registration statements.

Which registration statements are referenced for ECO?

Form F‑3 File No. 333‑287032 and File No. 333‑287036, both declared effective on May 21, 2025.

When was the ECO press release dated?

The press release is dated November 12, 2025.

Who signed the ECO Form 6‑K?

It was signed by Iraklis Sbarounis, Chief Financial Officer.