William Aloysius Bergen (June 13, 1878 – December 19, 1943) was an American professional baseball catcher. He played eleven seasons in Major League Baseball (MLB) from 1901 to 1911 for the Cincinnati Reds and Brooklyn Superbas/Dodgers. He was one of the worst-hitting position players in the history of the Major Leagues, but was also one of the best defensive catchers of all time.