William H. Colgan
- Bats Unknown, Throws Unknown
- Weight 180 lb.
- Debut May 3, 1884
- Final Game October 15, 1884
- Born March 19, 1862 in East St. Louis, IL USA
- Died August 8, 1895 in Great Falls, MT USA
Billy Colgan hit .155 in 48 games with the Pittsburgh Alleghenys in 1884, not earning another look. He was the first major leaguer in history to die in Montana, perishing in a railyard accident at the age of 33 in 1895. He is listed as "Ed Colgan" in some sources.