"Tithonus" is the tenth episode of the sixth season of the American science fiction television series The X-Files. It premiered on the Fox network on January 24, 1999. The episode was written by Vince Gilligan, and directed by Michael W. Watkins. The episode is a "Monster-of-the-Week" story, unconnected to the series' wider mythology. "Tithonus" earned a Nielsen household rating of 9.2, being watched by 15.90 million people in its initial broadcast.