Butch Cassidy's Wild Bunch was one of the loosely organized outlaw gangs operating out of the Hole-in-the-Wall, near Kaycee in Wyoming, a natural fortress of caves, with a narrow entrance that was constantly guarded. In the beginning, the gang was referred to as the "Hole in the Wall Gang" during the Old West era in the United States. It was popularized by the 1969 movie, Butch Cassidy and the Sundance Kid, and took its name from the original Wild Bunch. The gang was led by Butch Cassidy, and it included his closest friends Elzy Lay, the Sundance Kid, Tall Texan, News Carver, Camilla "Deaf Charley" Hanks, Laura Bullion, Flat-Nose Curry, Kid Curry, and Bob Meeks. They were the most successful train-robbing gang in history.

Robert LeRoy Parker, better known as Butch Cassidy, was an American train and bank robber and the leader of a gang of criminal outlaws known as the "Wild Bunch" in the Old West.