- Jun 1 12.59" (31.98 cm) rainfall, in Burlington, Kansas (state 24-hr record)
- Jun 1 British troops occupy Baghdad, Iraq
- Jun 1 Germany bans all Catholic publications
- Jun 1 Germany occupies Crete after Allied evacuation
- Jun 2 WWII: British Royal Navy captures U-110, its 1st German U-boat; after gathering valuable code machinery, they sink the vessel
- Jun 3 Attack on telephone exchange in Schiphol
- Jun 3 German occupiers stamp "J" on Jewish passports
- Jun 4 Republic of Croatia orders all Jews to wear a star with the letter Z
- Jun 5 German ammunition depot at medieval Smederovo Fortress, near Belgrade, Serbia explodes; kills close to 2,000
Szabo vs Nagurski
Jun 5 Sandor Szabo beats B Nagurski in St Louis, to become wrestling champ
- Jun 5 World War II: At least 4,000 people who hid in a tunnel die after a Japanese air attack on the Chinese city of Chongqing
- Jun 6 1st US Navy vessel constructed as mine layer, USS Terror (CM-5) launched from the Philadelphia Navy Yard
- Jun 6 MLB New York Giants use plastic batting helmets for 1st time
73rd Belmont
Jun 7 73rd Belmont: Eddie Arcaro wins aboard Whirlaway to claim first of 2 Triple Crowns
Partition Chromatography
Jun 7 Chemists Archer John Porter Martin and Richard L. M. Synge give the first demonstration of partition chromatography (separation of mixtures) at a meeting of the Biochemical Society held at the National Institute for Medical Research, Hampstead
45th US Open
Jun 7 US Open Men's Golf, Colonial CC, Fort Worth: In sweltering heat, Craig Wood wins by 3 strokes ahead of runner-up Denny Shute
- Jun 8 British & French troops overthrow pro-German Syria
- Jun 9 Archbishop De Young bans priests cooperating with Rijks radio
- Jun 11 2nd great raid on Jews of Amsterdam
- Jun 11 Vichy-French planes bomb Tel Aviv, killing 20 Jews
- Jun 14 Estonia loses 11,000 inhabitants as a consequence of mass deportations into Siberia
Wichita's Boeing Plant II
Jun 14 Ground broken for Boeing Plant II (ex-AFLC Plant 13) in Wichita, Kansas
- Jun 16 1st US federally owned airport opened Washington, D.C.
Louis KOs Conn
Jun 18 In his 18th world heavyweight title defence Joe Louis KOs Billy Conn in 13th round in front of a crowd of 54,487 at the Polo Grounds, NYC
- Jun 18 Turkey signs peace treaty with Nazi Germany
- Jun 19 Romania orders Jewish evacuation of Darabani
- Jun 19 Soviet anthropologist Michael Gerasimov opens tomb of Timurid Empire founder Timur and allegedly finds the inscription that whoever opens the tomb shall "unleash an invader more terrible than I." Three days later Germany invades Russia.
Two Ocean Navy Expansion Act
Jun 19 US President Franklin Roosevelt signs the Two Ocean Navy Expansion Act - increases the size of US Navy by 70%
Germany Invades the Soviet Union
Jun 22 Operation Barbarossa: Nazi Germany and its allies invade the Soviet Union during World War II, the largest military operation in history
- Jun 22 Various Communist and Socialist French Resistance movements merge to one group
- Jun 23 Germany occupies Telz, Lithuania
- Jun 24 Entire Jewish male population of Gorzhdy, Lithuania, exterminated
- Jun 24 Germans advance into Russia and take Vilna, Brest-Litovsk and Kaunas
- Jun 25 -26] Soviet counterattack at Rovno, Ukraine
- Jun 25 Fair Employment Practices Commission established
- Jun 25 Finland declares war on Soviet Union
- Jun 25 Finland enters WW2 against the USSR following a massive airstrike the previous day
- Jun 25 Germans invade Dubno Poland, giving permission to Ukrainians to do whatever they want to 12,000 Jews living there
Byrnes to Supreme Court
Jun 25 James F. Byrnes is admitted to the US Supreme Court
- Jun 25 US President Franklin D. Roosevelt signs Executive Order 8802, which forbids racial discrimination in the defense industry
- Jun 26 Lithuanian fascists massacre 2,300 Jews in Kovno
- Jun 27 Bialystok Poland falls to Germany
- Jun 27 Nazi manifest against the Jews in Amsterdam
- Jun 28 German and Romanian soldiers kill 11,000 Jews in Kishinev
- Jun 28 German troops occupy Galicia, Poland
- Jun 29 DiMaggio extends hitting streak to 42 breaking Sisler's record
- Jun 30 Ukrainian Nationalists (OUN) declare Ukraine independent
- Jun 30 World War II: Operation Barbarossa - Germany captures Lviv, Ukraine