"Tunguska" is the eighth episode of the fourth season of the American science fiction television series The X-Files. It premièred on the Fox network on November 24, 1996. It was directed by Kim Manners, and written by Frank Spotnitz and series creator Chris Carter. "Tunguska" featured guest appearances by John Neville, Nicholas Lea and Fritz Weaver. The episode helped explore the series' overarching mythology. "Tunguska" earned a Nielsen household rating of 12.2, being watched by 18.85 million people in its initial broadcast.

The fourth season of the American science fiction television series The X-Files commenced airing on the Fox network in the United States on October 4, 1996, concluding on the same channel on May 18, 1997, and contained 24 episodes. Following the filming and airing of the season, production began on The X-Files feature film, which was released in 1998 following the show's fifth season.