Star Wars: The Old Republic: Fatal Alliance is a science fiction novel from the Star Wars franchise written by Australian author Sean Williams. It is a prequel to and the first novel based on the MMORPG Star Wars: The Old Republic by BioWare Corp., and was released on July 20, 2010. The novel was first announced on November 10, 2008, by Sue Rostoni, the executive editor at Lucas Licensing, on the Starwars.com message boards.

Sean Llewellyn Williams is an Australian author of science fiction who lives in Adelaide, South Australia. Several of his books have been New York Times best-sellers.