Mark V. Olsen (born 1962) is a U.S. TV producer and screenwriter. He is the co-creator and executive producer of the HBO series Big Love along with writing partner and husband Will Scheffer. In 2007, Olsen and Scheffer won a TV Writers Guild of America Award for the pilot and first episode of Big Love.
Mark V. Olsen grew up in Hastings, Nebraska. He is also an attorney, and a member of the New York bar.
Olsen is openly gay; since the early 1990s, he and professional partner Will Scheffer have also been married to each other.
Prior to Big Love, Olsen co-produced Easter (2002), written by Will Scheffer. Olsen also wrote a six-part miniseries for HBO known as Mary Chestnut's Civil War.