星座能源美国存托凭证招股说明书（2026年6月2日版）

Common Stock The Selling Shareholders identified in this prospectus supplement are offering 11,000,000 shares of ourcommon stock, without par value (our “Common Stock”). We will not receive any of the proceeds from thesale of shares of our Common Stock by the Selling Shareholders. See “Description of Capital Stock” Subject to, and substantially concurrently with, the completion of this offering, we intend to purchasefrom the underwriters 2,000,000 shares of our Common Stock that are the subject of this offering at theprice paid to the Selling Shareholders by the underwriters in this offering. We refer to this proposed Following the completion of this offering and the Share Repurchase, we do not expect any shareholderwho received shares in connection with our acquisition of Calpine Corporation to beneficially own such Our Common Stock is listed on the Nasdaq Stock Market LLC (the “Nasdaq”) under the symbol“CEG.” On May29, 2026, the last sale price of our Common Stock as reported on the Nasdaq was $287.75 Investing in the Common Stock involves risks that are described in the “Risk Factors” section beginning onpageS-4of this prospectus supplement and under similar headings in the documents incorporated by reference The Selling Shareholders have granted the underwriters an option to purchase up to an additional1,350,000 shares of Common Stock at the public offering price, less the underwriting discount for a period Neither the U.S. Securities and Exchange Commission (“SEC”) nor any state securities commission hasapproved or disapproved of these securities or determined if this prospectus supplement or the The shares will be ready for delivery on or about June2, 2026. Morgan Stanley J.P. Morgan The date of this prospectus supplement is June1, 2026. TABLE OF CONTENTS We have provided you only with the information contained in this prospectus supplement, theaccompanying prospectus, and any free writing prospectus that we may provide to you. None of us, the SellingShareholders, or the underwriters have authorized anyone to provide you with different or additionalinformation. None of us, the Selling Shareholders, or the underwriters take any responsibility for, or can provideany assurance as to the reliability of, any other information that others may give you. This prospectussupplement does not constitute an offer to sell or a solicitation of an offer to buy any securities other than ourCommon Stock. Neither we, the Selling Shareholders, nor the underwriters are offering to sell shares of ourCommon Stock or seeking offers to buy shares of our Common Stock in any jurisdictions where offers and salesare not permitted. The information contained in this prospectus supplement, the accompanying prospectus, or ABOUT THIS PROSPECTUS SUPPLEMENT Unless the context indicates otherwise, references in this prospectus supplement to “we,” “us,” “our”and “Constellation” refer to Constellation Energy Corporation. References in this prospectus supplement to This document is in two parts. The first part is this prospectus supplement, which contains specificinformation about the terms on which the Selling Shareholders are offering and selling our Common Stockand important business information about us, and also adds to and updates information contained in theaccompanying prospectus dated January7, 2026, which forms a part of a registration statement onForm S-3(File No. 333-292608), and the documents incorporated by reference in this prospectus supplement and theaccompanying prospectus. The second part is the accompanying prospectus, which, among other things, This prospectus supplement and the accompanying prospectus do not contain all of the informationincluded in the registration statement, as permitted by the rules and regulations of the SEC. For furtherinformation, we refer you to our registration statement on Form S-3, including its exhibits, of which thisprospectus supplement and the accompanying prospectus form a part. We are subject to the informationalrequirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and therefore filereports and other information with the SEC. Statements contained in this prospectus supplement and the You should read both this prospectus supplement and the accompanying prospectus as well asadditional information incorporated by reference herein and described under “Where You Can Find MoreInformation” beginning on pageS-33of this prospectus supplement and “Documents Incorporated by If the description of this offering varies between this prospectus supplement and the accompanyingprospectus, you should rely on the information in this prospectus supplement. Any statement made in thisprospectus supplement or in a document incorporated or deemed to be incorporated by reference in thisprospectus supplement will be deemed to be modified or superseded for purposes of this prospectussupplement to the extent that a statement contained in this prospectus supplement