- Apr 1 400,000 US mine workers strike
- Apr 1 The Malayan Union is formed as a federation of the Malay states and the Straits Settlements of Penang and Malacca
- Apr 1 Tsunamis generated by a quake in Aleutian Trench strike Hilo, Hawaii
Ives' 3rd Symphony
Apr 5 1st performance of Charles Ives' 3rd Symphony
10th US Masters
Apr 7 10th US Masters Tournament, Augusta National GC: American Herman Keiser wins his only major title, 1 stroke ahead of tour money-leader Ben Hogan; first Masters in 4 years because of World War II
- Apr 7 Part of East Prussia incorporated into Russian SFSR
- Apr 7 Syria's independence from France is officially recognised.
- Apr 8 League of Nations assembles for the last time
- Apr 9 Stanley Cup Final, Montreal Forum, Montreal, Quebec: Montreal Canadiens beat Boston Bruins, 6-3 for a 4-1 series victory
- Apr 10 1st election for Japanese Parliament
LPGA Titleholders
Apr 12 LPGA Titleholders Championship Women's Golf, Augusta CC: Louise Suggs wins her first major title by 2 strokes from Eileen Stulb
- Apr 12 Syria gains independence from France
- Apr 13 Belgian Prime Minister Acker proclaims wage & price freeze ended
- Apr 13 Eddie Klepp, a white pitcher signed by defending Negro League champ Cleveland Buckeyes, is barred from field in Birmingham, Alabama
- Apr 14 Alan Jay Lerner and Frederick Loewe.'s musical "The Day Before Spring" closes at National Theater, NYC after 167 performances
- Apr 15 50th Boston Marathon won by Stylianos Kyriakides of Greece in 2:29:27; first and only Cypriot athlete to win the event
- Apr 16 1st US launch of captured V-2 rocket, White Sands, New Mexicao; reaches altitude of 8 km
- Apr 16 Dutch Special Court of Justice sentences Frederik Müller, Socialist mayor of Rotterdam, to 10 years in jail for his wartime support of Germany
Robinson 2nd Baseman
Apr 18 Jackie Robinson debuts as 2nd baseman for the Montreal Royals
- Apr 18 League of Nations dissolves (3 months after UN starts)
- Apr 18 Rome, Auerbach and Horwitt's musical "Call Me Mister" opens at National Theater, NYC; runs for 734 performances
Make Mine Music
Apr 20 Walt Disney's animated film anthology "Make Mine Music" premieres in New York City
Baseball Hall of Fame
Apr 24 11 players named to the Baseball Hall of Fame: Tinker, Evers, Chance, Burkett, McCarthy, Waddell, Plank, Walsh, Jack Chesbro, Griffith and McGinnity
Symphonic Variations
Apr 24 One-act ballet "Symphonic Variations" choreographed by Frederick Ashton with music by César Franck danced by Sandler's Wells Ballet debuts at Covent Garden, London
Feller's 2nd MLB No-Hitter
Apr 30 Cleveland Indians pitcher Bob Feller's 2nd career MLB no-hitter; beats New York Yankees, 1-0
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists