John Henry Neun (October 28, 1900 – March 28, 1990) was an American professional baseball player and manager. He played in Major League Baseball (MLB) as a first baseman from 1925 to 1931 for the Detroit Tigers and the Boston Braves. Neun is notable for completing the seventh unassisted triple play in MLB history. After his playing career he served as the manager for the New York Yankees and the Cincinnati Reds.