Star Wars Knights of the Old Republic II: The Sith Lords is a role-playing video game developed by Obsidian Entertainment and published by LucasArts. It is the sequel to BioWare's Star Wars: Knights of the Old Republic and was released for the Xbox on December 6, 2004, for Microsoft Windows on February 8, 2005, for OS X and Linux on July 21, 2015, for Android and iOS on December 18, 2020 and for Nintendo Switch on June 8, 2022. Like its predecessor, it is set in the Star Wars universe 4,000 years before the events of the film Episode I: The Phantom Menace and is based on the d20 System developed by Wizards of the Coast.

Obsidian Entertainment, Inc. is an American video game developer based in Irvine, California. It was founded in June 2003, shortly before the closure of Black Isle Studios, by ex-Black Isle employees Feargus Urquhart, Chris Avellone, Chris Parker, Darren Monahan, and Chris Jones.