Events in Sports History in May 1921

  • May 6 Teams from the National Association Football League and the Southern New England Soccer League merge to form the American Soccer League (ASL); collapses 1933
  • May 7 47th Kentucky Derby: Charles Thompson on Behave Yourself wins 2:04.2
  • May 16 46th Preakness: F Coltiletti aboard Broomspun wins in 1:54.2
  • May 30 Indianapolis 500: Tommy Milton accompanied by riding mechanic Harry Franck wins the first of two 500 victories after Ralph DePalma had led for 109 laps
  • May 31 Boston Red Sox 1st baseman John "Stuffy" McInnis begins an errorless string of 1,700 chances