List of Famous people who are 21

Donald O. Mitchell is an American sound engineer. He won an Oscar for Best Sound and was nominated for thirteen more in the same category. He worked on nearly 120 films between 1973 and 2002.

Thomas Robins is a New Zealand Producer, Director, Writer and Actor who was the original host of Squirt, a children's television series. He has also played roles in four films directed by Peter Jackson, the most notable being Déagol in The Lord of the Rings: The Return of the King.

Thomas W. L. "Tom" Sanford is an American plasma physicist who developed a multi-wire array for use in a pulsed Z-pinch plasma system which resulted in a breakthrough for inertial confinement fusion (ICF) research. In 2005, he was awarded the Hannes Alfvén Prize with Malcolm Haines and Valentin Smirnov for his contributions to the field.

Steve Rash is an American film director and producer best known for directing such films as Son In Law, The Buddy Holly Story, Can't Buy Me Love, Queens Logic, Bring It On: All or Nothing and Bring It On: In It to Win It.

Paul Austerberry is a Canadian production designer of English/Filipino descent. Best known for his work on the 2017 film, The Shape of Water, for which he won an Academy Award and a BAFTA Award for Best Production Design, with set decorators, Shane Vieau and Jeff Melvin.

David S. Touretzky is a research professor in the Computer Science Department and the Center for the Neural Basis of Cognition at Carnegie Mellon University. He received a BA in Computer Science at Rutgers University in 1978, and earned a master's degree and a Ph.D. (1984) in Computer Science at Carnegie Mellon University. Touretzky has worked as an Internet activist in favor of freedom of speech, especially what he perceives as abuse of the legal system by government and private authorities. He is a notable critic of Scientology.