John Ludy Riddle (October 3, 1905 – December 15, 1998) was an American professional baseball player and coach. He appeared in 98 games in Major League Baseball as a reserve catcher for the Chicago White Sox (1930), Washington Senators (1937), Boston Bees (1937–38), Cincinnati Reds (1941 and 1944–45) and Pittsburgh Pirates (1948). At the age of 42 in 1948 (as a player-coach), he was the oldest player to appear in a National League game that season. He was the older brother of Elmer Riddle, a star pitcher in the early 1940s as a member of the Reds.