Authors Born on December 21
- Jinato Hu Politician, 1942
- Joaquin Andujar Baseball Player, 1952
- Joe Paterno American Football Player, 1926
- John G. Avildsen Film Director, 1935
- John William McCormack Politician, 1891
- Kaitlyn Dever Actress, 1996
- Karishma Tanna Actress, 1984
- Karrie Webb Golfer, 1974
- Kay Robertson Television Presenter, 1947
- Kiefer Sutherland Actor, 1966
- Leopold von Ranke Historian, 1795
- Luigi Barzini Journalist, 1908
- Michael Horse Actor, 1949
- Michael Tilson Thomas Conductor, 1944
- Mikheil Saakashvili Politician, 1967
- Na Taejoo Actor, 1990
- Nancy Tillman Author, 1954
- Natalie Grant Singer, 1971
- Paco de Lucía Guitarist, 1947
- Paul Kurtz Philosopher, 1925
- Paul Revere Revolutionary, 1734
- Paul Winchell Comedian, 1922
- Petra Collins Artist, 1992
- Phil Donahue Writer, 1935
- Phil Humber Baseball Player, 1982
- Rachel Shenton Actress, 1987
- Ray Romano Stand-Up Comedian, 1957
- Samuel L. Jackson Film Actor, 1948
- Steve Mnuchin Politician, 1962
- Steven Mnuchin Investment Banker, 1962
- Steven Yeun Actor, 1983
- Thelma Plum Singer-Songwriter, 1994
- Thierry Mugler Fashion Designer, 1948
- U. R. Ananthamurthy Writer, 1932
- Walter Hagen Golfer, 1892
- Wen Ho Lee Scientist, 1939
- Yasmin Zarine Shahmir Singer, 1988
- Zev Yaroslavsky Politician, 1948
- Zoe Lofgren Politician, 1947