- May 3 Mayor Hylan closes 2 streets for building of Yankee Stadium in the Bronx, NYC
- May 5 After sharing the Polo Grounds with the New York Giants for 10 years construction begins on Yankee Stadium in the Bronx, NYC
- May 7 Belgian soccer team defeats Netherlands: 1-2
- May 7 NY Giant Jesse Barnes no-hits Phillies, 2-0
- May 13 47th Preakness: L Morris aboard Pillory wins in 1:51.6
- May 13 48th Kentucky Derby: Albert Johnson aboard Morvich wins in 2:04.6
Ruth and Meusel Return
May 20 Babe Ruth and Bob Meusel, previously suspended by Commissioner Kenesaw Mountain Landis, return to the NY Yankees lineup and go hitless
- May 21 Colonel Jacob Ruppert buys out Colonel Tillinghast L’Hommedieu Huston's interest in NY Yankees for $1,500,000 to become sole owner
- May 23 Future World Heavyweight boxing champion Gene Tunney suffers his only professional defeat in 15-round unanimous points decision against Harry Greb at Madison Square Garden, NY
- May 25 Babe Ruth suspended 1 day and fined $200 for throwing dirt on an umpire
- May 29 US Supreme Court rules organized baseball is a sport and not a business and thus not subject to antitrust laws
- May 30 Cubs and Cardinals trade outfielders between morning and afternoon games of doubleheader; Max Flack goes to St. Louis, Cliff Heathcote heads to Chicago; both get hits for new clubs in the nightcap
- May 30 Indianapolis 500: Jimmy Murphy becomes first driver to win the race from pole position; accompanied by riding mechanic Ernie Olson
Baseball Players
Basketball Stars
Boxers
Footballers
NFL Stars
Tennis Champions