Sean Whitesell was an American film and television actor, who is also a television writer and producer. He was born in Iowa Falls, Iowa. He studied acting at the University of California in San Diego, where he received an MFA in acting. Whitesell is best known for his portrayal of cannibalistic inmate Donald Groves, the initial cellmate of Miguel Alvarez (Kirk Acevedo), in season 1 of HBO's Oz, on which he was a regular until his character's execution.
In 2002, Whitesell returned to the show, but not to act; he wrote and produced several episodes in the show's later seasons. Whitesell has acted almost exclusively in television, aside from some early minor film roles, such as in Calendar Girl opposite Jason Priestley. He also served as both a writer and a recurring guest actor on Homicide: Life on the Street, in addition to appearing in the television movie that concluded the series in 2000. Although Whitesell has not acted since Homcide ended, he was a producer for most of the fourth season of House, and also wrote one episode, "Ugly". He produced and wrote for a few other recent successful series, including The Black Donnellys, Boston Public and Cold Case.
He died on December 28, 2015 in Los Angeles from cancer, aged 52.