William Francis Carrigan (October 22, 1883 – July 8, 1969), nicknamed "Rough", was a Major League baseball catcher and manager. He played for the Boston Red Sox between 1906 and 1916, and he was a player-manager for the last four of those seasons. In 1915 and 1916, Carrigan's teams won back-to-back World Series. He was said to exert a positive influence on young Red Sox star Babe Ruth, serving as his roommate and his manager. He has the highest postseason winning percentage (.800) of any manager with multiple postseason appearances, and was named to the Honor Rolls of Baseball in 1946.