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

For the month of June 2026

Commission File Number: 001-33283

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 1 is a copy of the press release issued by Euroseas Ltd. (the “Company”) on June 15, 2026: Euroseas Ltd. Announces Order for the Construction of Two Additional Feeder 1,800 TEU Containerships.

This Report on Form 6-K (which includes Exhibit 1), excluding the commentary by Chief Executive Officer Aristides Pittas, is hereby incorporated by reference into the Company’s Registration Statement on Form F-3 (File No. 333-268708) filed with the U.S. Securities and Exchange Commission (the “Commission”) on December 7, 2022.

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.

Exhibit 1

Euroseas Ltd. Announces Order for the Construction of Two Additional Feeder 1,800 TEU Containerships

Maroussi, Athens, Greece – June 15, 2026 – Euroseas Ltd. (NASDAQ: ESEA, the “Company” or “Euroseas”), an owner and operator of container carrier vessels and provider of seaborne transportation for containerized cargoes, announced today that it has declared its options for the construction of two additional modern fuel-efficient, gearless 1,800 teu container vessels to be built at Nantong CIMC Sinopacific Offshore & Engineering Co., Ltd, in China. The vessels are scheduled to be delivered in December of 2028 and March of 2029. The total consideration for each vessel is approximately $32.26 million and will be financed with a combination of debt and equity.

Aristides Pittas, Chairman and CEO of Euroseas commented: “We are very pleased to announce the ordering of two additional 1,800 teu gearless containerships, sisterships to the two we ordered in April of 2026. These orders reflect our continued commitment to disciplined fleet modernization and renewal. The feeder and sub-6000 teu containership market remains particularly tight. Combined with a low orderbook for this segment and an ageing existing fleet, we continue to see a compelling business case for investing in this vessel category and believe the structural fundamentals remain favorable.”

Fleet Profile:

The Euroseas Ltd. fleet profile is currently as follows:

Notes:

(*)

TC denotes time charter. Charter duration indicates the earliest redelivery date; all dates listed are the earliest redelivery dates under each TC unless the contract rate is lower than the current market rate in which cases the latest redelivery date is assumed; vessels with the latest redelivery date shown are marked by (+).

(**)

Charterer has the option to convert to a five-year charter at $32,500/day for the entire period.

(***)

The entity owning the vessel is 51% owned by Euroseas Ltd. and 49% by NRP Investors.

About Euroseas Ltd.

Euroseas Ltd. was formed on May 5, 2005 under the laws of the Republic of the Marshall Islands to consolidate the ship owning interests of the Pittas family of Athens, Greece, which has been in the shipping business over the past 150 years. Euroseas trades on the NASDAQ Capital Market under the ticker ESEA.

Euroseas operates in the container shipping market. Euroseas' operations are managed by Eurobulk Ltd., an ISO 9001:2008 and ISO 14001:2004 certified affiliated ship management company, which is responsible for the day-to-day commercial and technical management and operations of the vessels. Euroseas employs its vessels on spot and period charters and through pool arrangements.

The Company has a fleet of 21 vessels, including 15 Feeder containerships and 6 Intermediate containerships with a cargo capacity of 61,144 teu. After the delivery of four intermediate and eight feeder containership newbuildings between 2027 and 2029, Euroseas’ fleet will consist of 33 vessels with a total carrying capacity of 97,396 teu.

Forward Looking Statement

This press release contains forward-looking statements (as defined in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended) concerning future events and the Company's growth strategy and measures to implement such strategy; including expected vessel acquisitions and entering into further time charters. Words such as "expects," "intends," "plans," "believes," "anticipates," "hopes," "estimates," and variations of such words and similar expressions are intended to identify forward-looking statements. Although the Company believes that the expectations reflected in such forward-looking statements are reasonable, no assurance can be given that such expectations will prove to have been correct. These statements involve known and unknown risks and are based upon a number of assumptions and estimates that are inherently subject to significant uncertainties and contingencies, many of which are beyond the control of the Company. Actual results may differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially include, but are not limited to changes in the demand for containerships, competitive factors in the market in which the Company operates; risks associated with operations outside the United States; and other factors listed from time to time in the Company's filings with the Securities and Exchange Commission. The Company expressly disclaims any obligations or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in the Company's expectations with respect thereto or any change in events, conditions or circumstances on which any statement is based.

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