- Mar 1 Sergius Kagen, American pianist & composer, dies at 54
- Mar 6 Edward Van Sloan, American actor (Frankenstein, Dracula), dies at 81
- Mar 6 King Paul I, King of Greece (1947-64), dies at 62
- Mar 7 Franz Alexander, Hungarian-American pioneering psychoanalyst (pioneered psychosomatic medicine), dies at 73
- Mar 9 Johanna W "Mina" Bakker, Dutch actress (Boefje), dies at 87
- Mar 9 Paul von Lettow-Vorbeck, 'the Lion of Africa', German general and politician (only German to successfully invade part of British empire in WWI), dies at 93
- Mar 13 Catherine "Kitty" Genovese, stabbed to death in Queens; almost 40 witnesses but no rescuers
- Mar 15 Paul Cavanagh, British actor (The Woman in Green, Tarzan & his Mate), dies at 75
- Mar 16 Nicholas Joy, French actor (Gentleman's Agreement; Desk Set; Boss Lady), dies at 80
Norbert Wiener (1894-1964)
Mar 18 American mathematician who founded cybernetics, dies of a heart attack at 69
Brendan Behan (1923-1964)
Mar 20 Irish author and poet (Borstal Boy, The Hostage), dies at 41
- Mar 20 Jean Rogister, Belgian virtuoso violist and composer, dies at 84
- Mar 22 Addison Richards, American actor (Pentagon, Fighting Seabees), dies at 61
- Mar 23 Peter Lorre, Hungarian-American actor (M, Casablanca, Beast with 5 Fingers), dies from a stroke at 59
- Mar 23 Vasily Vainonen, Russian ballet choreographer (Gayaneh), dies at 66
- Mar 26 Hedwig Kohn, Prussian-born Jewish physics pioneer, dies at 77
- Mar 30 Nellallitea "Nella" Larsen [Nellie Walker], African-American Harlem Renaissance novelist (Quicksand, Passing), dies at 72
- Mar 30 Willem Andriessen, Dutch composer and pianist (Beethoven), dies at 76