- May 5 82nd Kentucky Derby: David Erb aboard Needles wins in 2:03.4
- May 5 Broekster Boys soccer team forms in Damwoude
- May 5 World championships of judo are 1st held in Tokyo
Baseball Record
May 18 Mickey Mantle hits HR from both sides of plate for record 3rd time
- May 19 81st Preakness: Bill Hartack aboard Fabius wins in 1:58.4
- May 19 Pittsburgh Pirates Dale Long hits 9th-inning HR, 1st HR in 8 straight games
French Open Men's Tennis
May 26 French Championships Men's Tennis: Australian Lew Hoad wins his first and only French title; beats Sven Davidson of Sweden 6-4, 8-6, 6-3
French Open Women's Tennis
May 26 French Championships Women's Tennis: American Althea Gibson wins her only French singles title; beats Angela Mortimer of England 6-0, 12-10
- May 26 Reds' John Klippstein, Hershel Freemman & Joe Blacks no-hitter, broken up with 2 outs in 10th & lose to Braves in 11th, 2-1
- May 28 Pittsburgh Pirates Dale Long becomes 1st to hit HRs in 8 straight games
- May 30 Indianapolis 500: Pat Flaherty wins in a Watson-Offenhauser; first 500 to be governed by the United States Automobile Club
- May 30 Mickey Mantle misses by 18 inches hitting 1st home run out of Yankee Stadium in the first game of a doubleheader against the Washington Senators