Icon Energy Corp美股招股说明书(2025-11-26版)

PROSPECTUS SUPPLEMENT NO. 1(to Prospectus dated September 22, 2025) Icon Energy Corp. This prospectus supplement is being filed to update, amend and supplement the information contained in the prospectus datedSeptember 22, 2025 (as supplemented or amended from time to time, the “Prospectus”), which forms a part of our RegistrationStatement on Form F-1 (Registration Statement No. 333-290206), with the information contained in our report on Form 6-K, filed The Prospectus relates to the sale from time to time of up to 10,357,237 common shares, par value $0.001, per share (“CommonShares”) of Icon Energy Corp., incorporated under the laws of the Marshall Islands, by YA II PN, Ltd., a Cayman Islands exempt This prospectus supplement updates, amends and supplements the information in the Prospectus and is not complete without, andmay not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. Thisprospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in Our Common Shares are currently listed on The Nasdaq Capital Market under the symbol “ICON.” On November 25, 2025, thelast reported sales price of our Common Shares was $1.00 per share. Investing in our securities involves a high degree of risk. You should carefully review the risks and uncertainties describedin the section titled “Risk Factors” beginning on page 6 of the Prospectus, and under similar headings in any amendments or Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to The date of this prospectus is November 26, 2025 UNITED STATESSECURITIES AND EXCHANGE COMMISSION Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-42174 Icon Energy Corp. (Translation of registrant’s name into English) c/o Pavimar Shipping Co.17th km National RoadAthens-Lamia & Foinikos Str.14564, Nea KifissiaAthens, Greece Indicate by check mark whether the registrant files or will file annual reportsunder cover of Form 20-F or Form 40-F: INFORMATION CONTAINED IN THIS FORM 6-K REPORT Attached to this report on Form 6-K asExhibit 99.1andExhibit 99.2are the unaudited interim condensed consolidatedfinancial statements and related management’s discussion and analysis of financial condition and results of operations of Icon Energy The information contained in this Form 6-K is deemed to be filed, not furnished, and shall be incorporated by reference intoany related future registration statements and Prospectuses, and as such Prospectuses may be amended from time to time. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed onits behalf by the undersigned, thereunto duly authorized. By:/s/ Dennis PsachosName:Dennis PsachosTitle: Chief Financial Officer