天空港集团股份有限公司-美国存托股份招股说明书(2025-12-15版)

SKY HARBOUR GROUP CORPORATION50,000 SHARES OF CLASS A COMMON STOCK We are issuing 50,000 shares of our Class A common stock, par value $0.0001 per share (“Class A Common Stock”), in aregistered direct offering to YA II PN, Ltd., a Cayman Islands exempt limited company, or its registered assigns (“Yorkville”),pursuant to this prospectus supplement and the accompanying prospectus. The shares are being issued in connection with andpursuant to the non-convertible unsecured promissory note issued to Yorkville (the “Yorkville Promissory Note”), which isdiscussed further herein. Our Class A Common Stock is traded on the New York Stock Exchange (“NYSE”) under the symbol “SKYH.” On December12, 2025, the last reported sale price on NYSE of our Class A Common Stock was $9.61 per share. Investing in our Class A Common Stock involves significant risks. Please read the information contained in orincorporated by reference under the heading“Risk Factors”beginning on page S-4of this prospectus supplement and otherreports incorporated by reference into this prospectus supplement and the accompanying prospectus, for a discussion of thefactors you should carefully consider before deciding to invest in our Class A Common Stock. Neither the Securities and Exchange Commission (the“SEC”) nor any state securities commission or other regulatorybody has approved or disapproved of our Class A Common Stock, or determined if this prospectus supplement or theaccompanying prospectus is accurate, truthful or complete. Any representation to the contrary is a criminal offense. The shares of Class A Common Stock are being offered directly to Yorkville without a placement agent, underwriter, broker ordealer. We will not receive any cash proceeds from this offering. We will bear all costs, expenses and fees in connection with theregistration of the shares and this offering. We expect to deliver the shares of our Class A Common Stock to Yorkville on or about December 15, 2025. Table of Contents TABLE OF CONTENTS Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENTCAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSPROSPECTUS SUPPLEMENT SUMMARYTHE OFFERINGRISK FACTORSUSE OF PROCEEDSPLAN OF DISTRIBUTIONLEGAL MATTERSEXPERTSWHERE YOU CAN FIND MORE INFORMATIONINCORPORATION BY REFERENCE Prospectus ABOUT THIS PROSPECTUSSUMMARYRISK FACTORSFORWARD-LOOKING STATEMENTSUSE OF PROCEEDSTHE SECURITIES WE MAY OFFERDESCRIPTION OF CAPITAL STOCKDESCRIPTION OF DEPOSITARY SHARESDESCRIPTION OF WARRANTSDESCRIPTION OF UNITSPLAN OF DISTRIBUTIONLEGAL MATTERSEXPERTSINCORPORATION OF CERTAIN INFORMATION BY REFERENCEWHERE YOU CAN FIND MORE INFORMATION ABOUT THIS PROSPECTUS SUPPLEMENT This document is part of the registration statement that we filed with the SEC using a “shelf” registration process and consistsof two parts. The first part is this prospectus supplement, which describes the specific terms of the offering of our Class A CommonStock offered hereby. The second part is the accompanying prospectus dated April 10, 2024 included in the registration statementon Form S-3 (333-278275), which gives more general information, some of which may not apply to the offering of our Class ACommon Stock offered hereby. Generally, when we refer only to the “prospectus,” we are referring to both parts combined. Thisprospectus supplement may add to, update or change information in the accompanying prospectus and the documents incorporatedby reference into this prospectus supplement or the accompanying prospectus. By using a shelf registration statement, we mayfrom time to time offer and sell any securities or combination of the securities described in the accompanying prospectus. Ifinformation in this prospectus supplement is inconsistent with the accompanying prospectus or with any document incorporated byreference that was filed with the SEC before the date of this prospectus supplement, you should rely on this prospectus supplement.This prospectus supplement, the accompanying prospectus and the documents incorporated into each by reference includeimportant information about us, the securities being offered and other information you should know before investing in oursecurities. You should also read and consider information in the documents we have referred you to in the section of this prospectussupplement entitled “Where You Can Find More Information; Incorporation of Documents by Reference.” We have not authorized anyone to provide you any information other than that contained or incorporated by reference in thisprospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by or on behalf of us or to whichwe have referred you. We do not take any responsibility for, and can provide no assurance as to the reliability of, any otherinformation that others may give you. You should assume that the information appearing in this prospectus supplement, theaccompanying prospectus and the documents incorporated by reference is accurate only as