This volume constitutes the proceedings of the 17th International Conference on Theorem Proving in Higher Order Logics (TPHOLs 2004) held September 14-17, 2004 in Park City, Utah, USA. TPHOLs covers all aspects of theorem proving in higher-order logics as well as related topics in theorem proving and veri?cation. There were 42 papers submitted to TPHOLs 2004 in the full research ca- gory, each of which was refereed by at least 3 reviewers selected by the program committee. Of these submissions, 21 were accepted for presentation at the c- ference and publication in this volume. In keeping with...