X-Factor Investigations Headquarters, New York City, New York; formerly Detroit, Michigan; mobile; Xaviers School for Gifted Youngsters, Salem Center, Westchester County, New York; Mojoverse; Cootermans Creek, Australian Outback, Australia; Alcatraz I
Currently unrevealed, formerly Asteroid M; various hidden bases on Earth including one in Antarctica; an island in the Bermuda Triangle; Professor Xaviers School for Gifted Youngsters, Salem Center, Westchester County, New York