Sith is a term applied to certain characters in the Star Wars universe capable of using the "dark side" of the Force. In the Star Wars films and much of the Expanded Universe they are the main antagonists.

The Star Wars series began with the film Star Wars, which was released in 1977. However, since 1977 books, computer games, comics, and films have been released, all set in the fictional universe of Star Wars, which has expanded the history of the Sith within the stories told in the Star Wars Universe.

Early Dark Jedi, who had warred against the Jedi were exiled to the planet Korriban, where they conquered a powerful but malleable indigenous species known as the Sith race. Treated like gods by their conquered people, they proclaimed themselves "Lords of the Sith." As time progressed, the Sith ruled an isolated part of the galaxy they called the Sith Empire; the capital was on the planet Ziost. The Empire fell because of the battle for supremacy between two Sith Lords, Ludo Kressh and Naga Sadow – a period called The Great Hyperspace War.

Eventually, a Sith Lord named Darth Bane was responsible for the destruction of all the Sith with the exception of himself and his apprentice, Darth Zannah, and managed to trick the Jedi Council into believing that the Sith were completely gone.He also created the "Rule of Two", which states "Two there shall be ... a master and an apprentice: one to embody power and the other to crave it."

Centuries later, Darth Sidious's schemes led to the Clone Wars, the destruction of the Jedi Council, and the transformation of the Galactic Republic into the Galactic Empire. However, the Sith were not completely victorious; Darth Vader and the Emperor attempted to turn Luke Skywalker to the dark side, but they failed and were defeated. In the end, Darth Vader chose the path of the Jedi once again and became one with the Force, appearing with Obi Wan Kenobi and Jedi Master Yoda at the end of Return of The Jedi.