As filed with the Securities and Exchange Commission on October 10, 2005 Registration No. 333-126896 SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ------------------------------------------ POST-EFFECTIVE AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Hennessy Advisors, Inc. (Exact name of registrant as specified in its charter) California 6282 68-0176227 (State or other (Primary Standard Industrial (I.R.S. Employer jurisdiction of Classification Code Number) Identification No.) incorporation or organization) 750 Grant Avenue, Suite 100 Novato, California 94945 (415) 899-1555 (Address, including zip code, and telephone number, including area code of Registrant's principal executive offices.) Neil J. Hennessy Chief Executive Officer Hennessy Advisors, Inc. 750 Grant Avenue, Suite 100 Novato, California 94945 (415) 899-1555 (Name, address, including zip code, and telephone number, including area code, of agent for service) Copies to: Linda Y. Kelso John F. Hartigan Foley & Lardner LLP Morgan, Lewis & Bockius LLP One Independent Drive, Suite 1300 300 South Grand Avenue, Twenty-Second Floor Jacksonville, Florida 32202-5017 Los Angeles, California 90071-3132 (904) 359-2000 (213) 612-2500 Approximate date of commencement of proposed sale to the public: As soon as practicable after this registration statement is declared effective. If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. |_| If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. |_| If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. |_| If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. |_| If delivery of the prospectus is expected to be made pursuant to Rule 434, check the following box. |_| Hennessy Advisors, Inc. hereby amends this Form S-1 registration statement for the purpose of deregistering all 1,822,463 shares of common stock covered by the registration statement. The registrant has elected to terminate its offering without selling any shares. SIGNATURES Pursuant to the requirements of the Securities Act of 1933, the registrant has caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Novato, State of California, on October 10, 2005. HENNESSY ADVISORS, INC. By: /s/ Neil J. Hennessy ------------------------------------- Neil J. Hennessy, Chief Executive Officer, President and Chairman of the Board Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates stated. NAME DATE ---- ---- /s/ Neil J. Hennessy October 10, 2005 -------------------------------------------------------------- Neil J. Hennessy, Chief Executive Officer, President, Chairman of the Board and Director /s/ Teresa M. Nilsen October 10, 2005 -------------------------------------------------------------- Teresa M. Nilsen, Chief Financial Officer, Chief Accounting Officer and Director /s/ Daniel B. Steadman October 10, 2005 -------------------------------------------------------------- Daniel B. Steadman, Director /s/ Brian A. Hennessy* October 10, 2005 -------------------------------------------------------------- Brian A. Hennessy, Director /s/ Daniel G. Libarle* October 10, 2005 -------------------------------------------------------------- Daniel G. Libarle, Director /s/ Rodger Offenbach* October 10, 2005 -------------------------------------------------------------- Rodger Offenbach, Director /s/ Thomas L. Seavey* October 10, 2005 -------------------------------------------------------------- Thomas L. Seavey, Director October 10, 2005 -------------------------------------------------------------- Charles W. Bennett, Director /s/ Henry Hansel* October 10, 2005 -------------------------------------------------------------- Henry Hansel, Director *By: /s/ Daniel B. Steadman October 10, 2005 ---------------------------------------------------------- Daniel B. Steadman, Attorney-in-Fact