Dark Jedi is a label to a specific archetype of characters in the Star Wars Expanded Universe defined as Force-attuned beings that meet two requirements: They do not hold themselves to the dogma of either the Jedi or the Sith, and they use their Force abilities for less than virtuous acts that would normally be looked down upon by the Jedi Order. As it has been mentioned, the concept of Dark Jedi is not endorsed anywhere within either movie trilogy. Dark Jedi in the Expanded Universe typically refer to students of Luke Skywalker's Jedi Academy who have fallen to the dark side. Dark Jedi are also extremely common in the Knights of the Old Republic series in league with the Sith Empire and are often fallen Jedi from the Mandalorian Wars. Dark Jedi also appear in the Jedi Knight series of Star Wars video games, where Kyle Katarn uncovers Imperial plots linked to Dark Jedi. In Jedi Outcast, Katarn faces an entire army of Dark Jedi, cloned and lightly trained force users who follow the main antagonist. Dark Jedi have distanced from Sith in more modern Star Wars media. They are not sworn enemies of the Jedi Order and do not consider destroying it a priority as Sith do. Dark Jedi do not always appear in pairs with a master and apprentice and often work alone.

Because the term Sith was never spoken in the original trilogy (although Darth Vader was described as "Lord of the Sith" in the published screenplay), early Expanded Universe products usually considered the "evil Jedi," those who joined the dark side of the Force, as "Dark Jedi." In his novel series The Thrawn Trilogy, author Timothy Zahn labeled Sith Lord Darth Vader and Emperor Palpatine as Dark Jedi, and the term "Sith" was never mentioned in the series until later reprints of the novels.