Half Acre Gym was a 4,000-seat multi-purpose arena in Laramie, in the U.S. state of Wyoming. It opened in 1928. It was home to the University of Wyoming Cowboys basketball team from 1928 until 1951 when it was replaced by the War Memorial Fieldhouse. The size of the arena was about a half acre, hence its name. When it opened, it was one of the nation's largest indoor arenas.