List of Famous people who are 21

Richard R. Hoover is a visual effects artist noted for his work on Armageddon, Superman Returns and Blade Runner 2049.

Mark N. Wegman is an American computer scientist known for his contributions to algorithms and compiler optimization. Wegman received his B.A. from New York University and his Ph.D. from the University of California, Berkeley. He joined IBM Research in 1975, where he currently serves as head of Computer Science. He is a member of the IBM Academy of Technology and a Fellow of the Association for Computing Machinery (1996) and the Institute of Electrical and Electronics Engineers. He became an IBM Fellow in 2007. He was elected to the National Academy of Engineering in 2010.

John P. Grotzinger is the Fletcher Jones Professor of Geology at California Institute of Technology and chair of the Division of Geological and Planetary Sciences. His works primarily focus on chemical and physical interactions between life and the environment. In addition to biogeological studies done on Earth, Grotzinger is also active in research into the geology of Mars and has made contributions to NASA's Mars Exploration Program.

Ronald "Ron/Ronnie" Butler, Jr. is a Bahamian-born American television actor, director and comedian who is best known for portraying Oscar, the clever receptionist, on the television series True Jackson, VP, from 2008 to 2011. He often portrays former President Barack Obama in comedy sketches. He has performed with the Atlantic Theater Company for over 20 years.

John Myhre is an American production designer who has been working in Hollywood since the late 1980s.

Rick Simpson is an American set decorator. He won an Academy Award and was nominated for another in the category Best Art Direction.

Gary J. Brink is an American set decorator. He won an Oscar in the category Best Art Direction for the film All That Jazz.

Aldo Signoretti is an Italian make-up artist. He has been nominated three times for the Academy Award for Best Makeup, the first time for his work in Moulin Rouge! (2001), the second time for his work in Apocalypto (2006), and the third time for his work in Il divo (2010).

Robert Ward Vishny is an American economist and is the Myron S. Scholes Distinguished Service Professor of Finance at the University of Chicago Booth School of Business. He was the Eric J. Gleacher Distinguished Service Professor of Finance at the University of Chicago Booth School of Business.