List of Famous people who are 21

Marcia Jean Kurtz is an American film, stage, and television actress and director. She has appeared in such films as The Panic in Needle Park, In Her Shoes, Dog Day Afternoon and Big Fan. Kurtz won an Obie Award for her performance as Doris in Donald Margulies' The Loman Family Picnic. She was also nominated for both an Obie and a Drama Desk Award for her role in Martin Sherman's When She Danced. Kurtz also directed Matty Selman's Uncle Phillip's Coat and Evan Handler's Time of Fire.

Mark Newman is an English-American physicist and Anatol Rapoport Distinguished University Professor of Physics at the University of Michigan, as well as an external faculty member of the Santa Fe Institute. He is known for his fundamental contributions to the fields of complex networks and complex systems, for which he was awarded the 2014 Lagrange Prize.