Benitec Biopharmaceuticals Co., Ltd. American Depository Share Prospectus (Version as of June 2, 2025)

PROSPECTUS 900,000 Shares of Common Stock This prospectus relates to the resale by the Selling Stockholders named in this prospectus (the “Selling Stockholders”) of 900,000 shares of commonstock, par value $0.0001 per share (the “Common Stock”), of Benitec Biopharma Inc. (the “Company”). We are registering the resale of these shares of Common Stock to satisfy certain registration rights we have granted pursuant to the terms of theRegistration Rights Agreement (as defined in the prospectus). We entered into the Registration Rights Agreement in connection with our registereddirect offering that closed on March26, 2025. We will not receive any of the proceeds from the sale of the Common Stock by the Selling Stockholders. The registration for resale of the shares of Common Stock covered by this prospectus does not mean that the Selling Stockholders will offer or sell anyof the shares of Common Stock. The Selling Stockholders may sell the shares of Common Stock covered by this prospectus in a number of differentways and at varying prices. For additional information on the possible methods of sale that may be used by the Selling Stockholders, you should refer to Our common stock is listed on The Nasdaq Capital Market under the symbol “BNTC.” On May30, 2025, the last reported sale price of our CommonStock on The Nasdaq Capital Market was $15.36 per share. Investing in our securities involves risks. You should carefully consider the risk factors included under the heading“Risk Factors” in this prospectus and under that heading or similar headings in the other documents incorporated byreference in this prospectus or any supplement to this prospectus before making a decision to purchase our securities. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities describedin this prospectus or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense. The date of this prospectus is June 2, 2025. TABLE OF CONTENTS Pageiiii14681 Table of Contents ABOUT THIS PROSPECTUS Unless the context otherwise requires, the terms “Benitec,” the “Company,” “we,” “us,” “our” and similar terms used in this prospectus refer to BenitecBiopharma Inc., a Delaware corporation, and its subsidiaries. This prospectus is part of a registration statement on FormS-3that we filed with the Securities and Exchange Commission (“SEC”). You should relyonly on the information contained in or incorporated by reference into this prospectus or contained in any free writing prospectus or prospectussupplement prepared by or on behalf of us or to which we have referred you. We have not, and the Selling Stockholders have not, authorized anyone toprovide you with information that is different from that contained in such prospectus or prospectus supplement. The Selling Stockholders are offering tosell shares of Common Stock, and are seeking offers to buy shares of Common Stock, only in jurisdictions where such offers and sales are permitted.For investors outside the United States: We have not, and the Selling Stockholders have not, taken any action that would permit this offering or You should read this prospectus and the information incorporated by reference in this prospectus before making an investment in our securities. See“Documents Incorporated by Reference” and “Where You Can Find More Information” for more information. You should rely only on the informationcontained in or incorporated by reference in this prospectus. We have not authorized anyone to provide you with different information. This prospectusand the information incorporated herein by reference contain summaries of certain provisions contained in some of the documents described herein, but We further note that the representations, warranties and covenants made by us in any document that is filed as an exhibit to the registration statement ofwhich this prospectus is a part and in any document that is incorporated by reference herein were made solely for the benefit of the parties to suchagreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a TRADEMARKS AND TRADENAMES We have proprietary and licensed rights to trademarks used in this prospectus which are important to our business, many of which are registered underapplicable intellectual property laws. These trademarks include: •BENITEC BIOPHARMA•BENITEC® Table of Contents Solely for convenience, trademarks and trade names referred to in this prospectus appear without the “®” or “™” symbols, but such references are notintended to indicate, in any way, that we will not assert, to the fullest extent possible under applicable law, our rights or the rights of the applicablelicensor to these trademarks and trade names. We do not intend our use or display of other companies’ trade names, trademarks or service marks to Tabl