Authors Born on March 21
- Nobuo Uematsu Video Game Developer, 1959
- Nora Barnacle Public Person, 1884
- Ogyu Sorai Philosopher, 1666
- Peter Brook Producer, 1925
- Phyllis McGinley Author, 1905
- Rachael MacFarlane Voice Actor, 1976
- Rani Mukerji Actress, 1978
- Raoul Vaneigem Writer, 1934
- Rhys Darby Actor, 1974
- Rochelle Humes Singer, 1989
- Ronald Koeman Football Manager, 1963
- Sabrina Marie Le Beauf Actress, 1958
- Sanha Singer, 2000
- Santino Fontana Actor, 1982
- Scott Eastwood Actor, 1986
- Sean McDermott American Football Manager, 1974
- Sergey Lavrov Diplomat, 1950
- Suraj Sharma Actor, 1993
- Tagg Romney Businessperson, 1970
- Ustad Bismillah Khan Musician, 1916
- Vivian Stanshall Singer-Songwriter, 1943
- Walter Gilbert Physicist, 1932
- Wayne Jacobsen Author, 1953
- Wilson Follett Writer, 1887