Authors Born on April 21
- Additi Gupta Actress, 1988
- Aiden Wilson Tozer Pastor, 1897
- Alistair Maclean Novelist, 1922
- Andie MacDowell Actress, 1985
- Andre Siegfried Writer, 1875
- Anthony Quinn Actor, 1915
- Anwar Robinson Singer-Songwriter, 1979
- Arthur William Galston Botanist, 1920
- Asahel Nettleton Theologian, 1783
- Barbara Park Writer, 1947
- Bob Varsha Announcer, 1951
- Brian J. White Actor, 1975
- Bridget Everett Comedian, 1972
- Catherine Ingram Author, 1952
- Charles Grodin Actor, 1935
- Charlotte Bronte Novelist, 1816
- Chris Whitty Physician, 1966
- Christian Coma Drummer, 1985
- Claire Denis Film Director, 1946
- Dan O'Neill Caricaturist, 1942
- Daniel Goldstein Psychologist, 1969
- David Choe Painter, 1976
- Dylan Bruce Actor, 1980
- Ed Belfour Ice Hockey Player, 1965
- Edgar Fiedler Economist, 1929
- Elaine May Actress, 1932
- Emily Prager Author, 1948
- Erastus Wiman Journalist, 1834
- Erik King Actor, 1963
- Eve Arnold Photographer, 1912
- Frank Dillane Actor, 1991
- Fredrik Bajer Writer, 1837
- Gabriela Isler Model, 1988
- Garrett Hardin Ecologist, 1915
- Gary Condit Politician, 1948
- Georgia Harkness Theologian, 1891
- Hippolyte Taine Critic, 1828
- Iggy Pop Singer, 1947
- Isco Football Player, 1992
- James Dobson Author, 1936