Shin Takarajima
Apr 1 "Shin Takarajima" (New Treasure Island) by Osamu Tezuka published, first manga cartoon in tankōbon form
- Apr 1 1st Jewish immigrants to Israel disembark at Port of Eilat
- Apr 2 Carlo Terron's "Il diamente del profeta" premieres in Rome
- Apr 3 Sidney Lippman, Sylvia Dee, and Max Schulman's musical comedy "Barefoot Boy with Cheek", based on Schulman's novel of the same name, opens at Martin Beck Theatre, NYC; runs for 108 performances
- Apr 4 Largest group of sunspots on record
- Apr 4 United Nation's Convention on International Civil Aviation forms the International Civil Aviation Organization
11th US Masters
Apr 6 11th US Masters Tournament, Augusta National GC: Jimmy Demaret wins his 2nd Masters by 2 strokes over Byron Nelson and amateur Frank Stranahan
1st Tony Awards
Apr 6 1st Tony Awards: Arthur Miller, David Wayne & Patricia Neal win for theatrical achievements
Leo Durocher Suspended
Apr 9 Baseball Commissioner Happy Chandler suspends Brooklyn Dodger Leo Durocher for 1 year for "association with known gamblers"
- Apr 9 Tornadoes striking West Texas & Oklahoma kill 169, injuring 1,300
Jackie Robinson's MLB Contract
Apr 10 Jackie Robinson becomes first black player of the 20th century to sign a MLB contract; Brooklyn GM, Branch Rickey announces Dodgers had bought Robinson’s contract from Montreal Royals
- Apr 10 King Frederik IX of Denmark crowned
- Apr 15 Jackie Robinson becomes the first African-American to play in US major league baseball (Dodgers)
- Apr 15 Operations begin at Radio Netherlands World radio
- Apr 16 -17] Explosions & fire on French ship Grandcamp
- Apr 16 Fire aboard French-flagged cargo ship SS Grandchamp, docked at Port of Texas City, Texas and loaded with 2,300 tons of ammonium nitrate causes massive explosion and spreads to nearby ships and oil facilities; deadliest industrial accident in US history kills 581, including all but one member of the city's fire departments
- Apr 16 Lens to provide zoom effects demonstrated (NYC)
- Apr 17 Jackie Robinson bunts for his 1st major league hit
New Orleans
Apr 18 "New Orleans", an American musical romance film premieres; Louis Armstrong and Billie Holiday, in her only feature film, play supporting roles
- Apr 19 AAU record for a 25-foot rope climb is set in 4.7 seconds
Maurice Richard Named MVP
Apr 19 After scoring 45 goals during the regular season, Montreal Canadiens' Maurice Richard is named MVP
- Apr 19 England beats France, 6-3 at Twickenham to be level on points with Wales for a share of the Five Nations Rugby Championship; first appearance of France in tournament since 1931
- Apr 19 Stanley Cup Final, Maple Leaf Gardens, Toronto, Ontario: Toronto Maple Leafs edge Montreal Canadiens, 2-1 for a 4-2 series win; first all-Canadian final since 1935
- Apr 19 Suh Yun Buck wins world record marathon (2:25:39)
- Apr 20 Frederik IX becomes King of Denmark
- Apr 21 51st Boston Marathon won by Yun Bok Soh of Korea in 2:25:39; world best time
- Apr 22 1st Basketball Association of America Finals: Philadelphia Warriors beat Chicago Stags, 83-80 to take inaugural series, 4 games to 2
- Apr 25 Trial against WW II mayor of Amsterdam Edward Voete begins
- Apr 26 Vivian Ellis and A. P. Herbert' musical "Bless the Bride" opena at the Adelphia Theatre in London; runs for 886 performances
Voyage of the Kon-Tiki
Apr 28 Thor Heyerdahl and the crew of the "Kon-Tiki" sail from Peru to Polynesia
- Apr 30 Boulder Dam renamed in honor of Herbert Hoover
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists