- May 4 Carl von Ossietzky, German pacifist and writer (Nobel Peace Prize 1935), dies at 48
- May 4 Kanō Jigorō, Japanese educator and the founder of Judo, dies at 77
- May 9 Thomas B. Thrige, Danish industrialist, dies at 72
- May 10 Percy McAlister, Australian cricket batsman (8 Tests; Big Six cricket dispute 1912), dies at 68
- May 11 Arnold Sauwen, Flemish poet (Hours of Solitude), dies at 81
- May 13 Charles Edouard Guillaume, French physicist (1920 Nobel Prize for Physics), dies at 77
- 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, dies at 60
- May 26 John Jacob Abel, American Pharmacologist (endocrine glands), dies at 81
- May 30 Raden Soetomo, Indonesian freedom fighter, dies at 49