- May 1 1st edition of illegal "The Free Artist" appears in Amsterdam
- May 1 69th Kentucky Derby: Johnny Longden wins aboard heavy favourite Count Fleet in the 'street car Derby'
- May 1 Food rationing begins in US
- May 1 German Wehrmacht deployed in order to break Dutch strikes
- May 1 German plane sinks boat loaded with Palestinian Jews bound for Malta
- May 1 Rauter signs unofficial death sentence
- May 2 German troops vacate Jefna, Tunisia
Event of Interest
May 3 Pulitzer prize awarded to Upton Sinclair (Dragon's Teeth)
Upton Sinclair
- May 3 Strike against obligatory labor camps ends, after 200 killed
- May 3 US 1st armour division occupies Mateur Tunisia
- May 4 NL Ford Frick demonstrates revised balata ball to reporters by bouncing it on his office carpet ball proves to be 50% livelier
- May 5 Postmaster General Frank C Walker invents Postal Zone System
- May 6 British 1st army opens assault on Tunis
- May 7 British 11th Hussars occupy Tunis
- May 7 Dutch men 18-35 obliged to report to labor camps
- May 7 Liberty Ship George Washington Carver, named after scientist, launched
- May 7 US 1st Armour division occupies Ferryville, Tunisia
- May 7 US 9th Infantry division occupies Bizerta/Bensert, Tunisia
- May 8 68th Preakness: Johnny Longden aboard Count Fleet wins in 1:57.4
- May 8 Admiral Cunningham of British fleet: "Sink, burn & destroy; let nothing pass"
- May 9 5th German Panzer army surrenders in Tunisia
- May 9 Rotschild-Haddassh University Hospital opens
Event of Interest
May 11 Hermann Goering division in Tunisia surrenders
Hermann Goering
Event of Interest
May 12 British premier Winston Churchill arrives in USA
Winston Churchill
- May 12 German troops in Tunisia North Africa surrender
- May 13 German & Italian forces in Africa surrender
- May 13 German occupiers attempt to confiscate all radios in the Netherlands
- May 14 Sinking of the Australian Hospital Ship Centaur off the coast of Queensland, by a Japanese submarine
- May 15 Halifax bombers sinks U-463
Event of Interest
May 15 Joseph Stalin dissolves the Comintern (or Third International)
Joseph Stalin
- May 16 Operation Chastise: No. 617 Squadron RAF begins the famous Dambusters Raid, bombing the Möhne and Eder dams in the Ruhr valley with bouncing bombs
- May 16 SS General Jürgen Stroop orders the burning of the Warsaw Ghetto, ending a month of Jewish resistance. 13,000 Jews have died, about half burnt alive or suffocated, German casualties less than 300
- May 17 The United States Army contracts with the University of Pennsylvania's Moore School to develop the ENIAC (Electronic Numerical Integrator And Computer).
- May 17 World War II: the Dambuster Raids by No. 617 Squadron RAF on German dams
Event of Interest
May 17 Millionaire Howard Hughes crashes into Lake Mead, while test flying his Sikorsky S-43, killing CAA inspector Ceco Cline and Richard Felt
Howard Hughes
- May 18 Allied bombers attack Pantelleria, an Italian island 100 km southwest of Sicily
- May 19 Berlin is declared "Judenrien" (free of Jews)
- May 19 Churchill pledges Britain's full support to US against Japan
- May 20 French, British and US victory parade in Tunis, Tunisia
- May 21 Fastest 9 inning AL baseball game (89 mins), White Sox beat Senators
- May 22 RAF scatters 1st copies of "The Flying Hollander"
- May 22 Stalin disbands Komintern
- May 23 -24] 826 Allied bombers attack Dortmund
Event of Interest
May 23 Thomas Mann begins writing his novel Dr Faustus
Thomas Mann
Event of Interest
May 24 Admiral Donitz stops U-boat in Atlantic Ocean
Karl Dönitz
Event of Interest
May 25 Agnes Moorehead appears in "Sorry, Wrong Number" on the radio program "Suspense", her most successful appearance
Agnes Moorehead
- May 26 Edwin Barclay of Liberia becomes first president of a black country to visit US
- May 26 Jews riot against Germany in Amsterdam
- May 26 Prime Minister Winston Churchill & General Marshall fly from US to North Africa
- May 27 French resistance under Jean Moulin meets secretly in Paris
- May 27 US forbids racial discrimination in war industry
Event of Interest
May 29 Confederacy of Algiers (Churchill-Marshall-Eisenhower)
Dwight D. Eisenhower
- May 29 Meat and cheese rationed in US
Event of Interest
May 30 French general Charles de Gaulle arrives in Algiers
Charles de Gaulle