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 and Scheffer wrote an independent film, Easter (2002). Olsen also wrote a six-part miniseries for HBO known as Mary Chestnut's Civil War.