- May 1 Charlie Robertson of Chicago pitches a perfect no-hit, no-run game
- May 2 WBAP-AM begins broadcasting from Fort Worth, Texas
- May 3 Mayor Hylan closes 2 streets for building of Yankee Stadium in the Bronx, NYC
- May 3 Salt layer find at Winterswijk
- May 4 KNX-AM in Los Angeles CA begins radio transmissions
- 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
Historic Event
May 9 The International Astronomical Union formally adopt Annie Jump Cannon's stellar classification system, which with only minor changes, is still used today
- May 10 Dr Ivy Williams is 1st woman to be called to the English Bar
- May 10 WHB-AM in Kansas City MO begins radio transmissions
- May 10 The United States annexes the Kingman Reef in n the North Pacific Ocean
- May 13 48th Kentucky Derby: Albert Johnson aboard Morvich wins in 2:04.6
- May 13 47th Preakness: L Morris aboard Pillory wins in 1:51.6
- May 15 Germany turns over the Upper Silesia region to Poland under Allied pressure and despite a plebiscite in favor of merging with Germany
- May 16 White Star Liner Majestic completes 5½ day maiden voyage
- May 18 Dutch 2nd Chamber agrees to 48 hour work week (was 45 hrs)
- May 20 "Egypt" sinks off Ushant after colliding with "Seine" killing 90
Sports History
May 20 Babe Ruth and Bob Meusel, previously suspended by Judge Kenesaw Mountain Landis, return to the NY lineup and go hitless
Historic Event
May 21 Pulitzer prize awarded to Eugene O'Neill for his play "Anna Christie"
- May 23 Comedic play "Abie's Irish Rose" premieres at Fulton Theatre, NYC; runs for 2,327 performances (longest run at the time)
- 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
Film & TV History
May 23 Walt Disney incorporates his 1st film company Laugh-O-Gram Films
Historic Event
May 26 Vladimir Lenin suffers a stroke
Historic Event
May 30 Completed Lincoln Memorial dedicated by US Chief Justice William Howard Taft in front of 50,000
- 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