Dorothy Catherine "D. C." Fontana (born March 25, 1939) was an American television script writer and story editor, best known for her work on the original Star Trek franchise and several western television series. After she attended Fairleigh Dickinson University, she moved to New York City briefly to work for Screen Gems as a secretary, but soon moved to Los Angeles where she worked in the typing pool at Revue Studios. She became the secretary for Samuel A. Peeples, who she sold her first story, "A Bounty for Bill", for the series The Tall Man. Her initial work was credited under the name Dorothy C. Fontana.
After Peeples left the studio, she moved to work for Del Reisman, a producer on The Lieutenant. The show was created by Gene Roddenberry, and after his secretary fell ill, Fontana covered. The Lieutenant was cancelled after one season, and Roddenberry began working on Star Trek. He had her work up one of his ideas into the episode "Charlie X", and after she re-wrote "This Side of Paradise", he gave her the job of story editor. She continued in this post until the end of the second season when she wanted to pursue her freelance writing work. She was nominated for a Writers Guild of America Award for an episode of Then Came Bronson.
Roddenberry brought Fontana back to write for Genesis II, and then as story editor and associate producer on Star Trek: The Animated Series. During the 1970s she worked on a number of series such as Logan's Run, the Six Million Dollar Man and Buck Rogers in the 25th Century. Roddenberry hired her to work on Star Trek: The Next Generation, but while she was given an associate producer credit, the experience soured the relationship with Roddenberry and resulted in a claim put to the Writers Guild of America. She later wrote an episode of Star Trek: The Next Generation as well as the plots for several of the franchise's video games, in addition to a comic story and an episode of the fan-made series Star Trek: New Voyages. She was awarded the Morgan Cox Award in 2002 by the Writers Guild of America, and named twice to the American Screenwriters Association's hall of fame.
D. C. Fontana died December 2, 2019, after a brief illness.