Betrayer of Worlds is a science fiction novel by Larry Niven, part of the Known Space universe. It explores themes of loyalty, betrayal, and the complexities of interstellar politics through the lens of advanced alien civilizations and human interactions.

The novel follows the story of the Puppeteers, a highly advanced alien race, as they navigate the treacherous waters of galactic politics and their own survival. The narrative delves into the consequences of betrayal and the moral dilemmas faced by its characters.