- May 4 Carl von Ossietzky, German pacifist and writer (Nobel Peace Prize 1935), dies at 48
- May 9 Thomas B. Thrige, Danish industrialist (b. 1866)
- May 10 Percy McAlister, cricketer (8 Tests, punches Clem Hill in 1912), dies
- May 11 Arnold Sauwen, Flemish poet (Hours of Solitude), dies at 81
- May 13 Charles Edouard Guillaume, Nobel Prize laureate (b. 1861)
- May 14 Jacobus C J "Jacques" Hermans, actor (Ghetto), dies at 81
- May 16 Stephen Fairbairn, oarsman/coach, dies
- May 17 Jakob Ehrlich, Austrian politician and zionist (b. 1877)
- May 23 Philip Kleintjes, republic leader, dies at 70
- May 26 John Jacob Abel, American Pharmacologist (endocrine glands), dies at 81
- May 30 Raden Soetomo, Indonesian freedom fighter, dies at 49