"Unusual Suspects" is the third episode of the fifth season of the American science fiction television series The X-Files and the 100th episode overall. It was written by Vince Gilligan and directed by Kim Manners and it originally aired in the United States on November 16, 1997 on the Fox network. The episode earned a Nielsen household rating of 13.0, being watched by 21.72 million people in its initial broadcast and received mixed to moderately positive reviews from critics.

The fifth season of the science fiction television series The X-Files commenced airing on the Fox network in the United States on November 2, 1997, concluding on the same channel on May 17, 1998, and contained 20 episodes. The season was the last in Vancouver, British Columbia, Canada; subsequent episodes would be shot in Los Angeles, California. In addition, this was the first season of the show where the course of the story was planned, due to the 1998 The X-Files feature film being filmed before it, but scheduled to be released after it aired.