The integration of TiO2 with a AuI complex containing a thiocoumarin moiety resulted in a very efficient photocatalyst for the generation of H2. The molecular structure of the complex was preserved under the photoreaction owing to the strong AuI−S bond. The AuI complex played a determinant role in the photogeneration of H2 by accepting the photoinduced electrons originated in TiO2 upon light exposure. This is the first example of a AuI complex semiconductor hybrid photocatalyst. The rate of H2 generation under dynamic conditions from water/ethanol is approximately one order of magnitude superior on a metal basis to that obtained over conventional TiO2 decorated with Au metal nanoparticles.