Clarence Kummer (August 8, 1899 - December 18, 1930) was a U.S. Racing Hall of Fame jockey who won four American Classic Races.In early 1920, Kummer rode the 1919 Triple Crown Champion Sir Barton to a new Saratoga track record in winning the Saratoga Handicap. In May 1920 he was given the opportunity to ride Man o' War. He rode the horse to nine wins in nine starts.