- Apr 1 Hippolyte Delehaye, Flemish historian, dies at 81
- Apr 2 Pál Teleki, prime minister of the Kingdom of Hungary (1920-1 and 1939-41), dies at 61
- Apr 3 Pal Teleki-von Szek, PM Hungary (1920-21, 39-41), suicide at 61
- Apr 4 Max Frisch, writer, dies at 29
- Apr 5 Sir Nigel Gresley, Steam locomotive engineer (b. 1876)
Annie Jump Cannon
Apr 13 Annie Jump Cannon, US astronomer (Henry Draper catalogues), dies at 77
Annie Jump Cannon
- Apr 14 Jack Edmonson, Australian corporal in Tobruk (Victoria Cross), dies
- Apr 14 Guillermo Kahlo, German-Mexican photographer and father of Frida Kahlo, dies at 69
- Apr 16 Josiah Charles Stamp, 1st baron/statisician, dies
- Apr 16 Josiah Stamp, 1st Baron Stamp, British civil servant, industrialist, economist, statistician and banker, dies at 60
- Apr 17 Al Bowlly, British dance band vocalist (b. 1899)
- Apr 18 ... Korysis, PM of Greece, commits suicide
- Apr 19 Johanna Muller-Hermann, composer, dies at 63
- Apr 20 Barend ter Haar, Dutch lawyer, dies in Buchenwald at 49
- Apr 22 Arthur Briscoe, cricketer (South African batsman in 2 Tests), dies
- Apr 24 Karin Boye, Swedish writer (Kallocain) commits suicide at 40
- Apr 26 Jean Demoor, Belgian physician and physiologist, dies at 74
- Apr 27 Penelope Delta, Greek author (b. 1874)