"Red Museum" is the tenth episode of the second season of the science fiction television series The X-Files. It premiered on the Fox network on December 9, 1994. It was written by Chris Carter, directed by Win Phelps, and featured guest appearances by Mark Rolston, Paul Sand, Bob Frazer, and Robert Clothier. The episode helps to explore the series' overarching mythology. "Red Museum" earned a Nielsen household rating of 10.4, being watched by 9.9 million households in its initial broadcast. The episode received mixed to positive reviews from critics.

The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files. In the episode, Mulder and Scully travel to Wisconsin after several teens are found wandering in the woods in their underwear with “He Is One” or “She Is One” scrawled on their backs. However, the duo soon stumble upon a strange cult of vegetarian “walk-ins.”

Originally, the episode was slated to be a crossover episode with the CBS show Picket Fences. However, the networks nixed the idea before any filming could begin. A facet of the episode, that the adherents of the Red Museum believe that the year 2012 will bring about the dawning of The New Age, is later referenced in the series' finale "The Truth", seven seasons later.