Mark Frost is an American novelist, screenwriter, film and television producer and director. He is the co-creator of the mystery television series Twin Peaks and was a writer and executive story editor of Hill Street Blues (1982–1985).

Mark Frutkin is a Canadian novelist and poet. He has published ten books of fiction, three books of poetry, as well as two works of non-fiction and a book of essays. In 2022, his novel The Artist and the Assassin won the Silver Medal in the IPPY Awards, in the category of literary fiction. In 2007, his novel, Fabrizio's Return, won the Trillium Prize for Best Book in Ontario and the Sunburst Award for Canadian Literature of the Fantastic, and was nominated for the Commonwealth Writers' Prize for Best Book. In 1988, his novel, Atmospheres Apollinaire, was short-listed for a Governor General's Award and was also short-listed for the Trillium Award, as well as the Ottawa-Carleton Book Award. His works have been shortlisted for the Ottawa Book Awards five times.

Mark Galeotti is a British historian, lecturer and writer on transnational crime and Russian security affairs and director of the consultancy Mayak Intelligence. He is an honorary professor at the UCL School of Slavonic and East European Studies, a senior associate fellow at the Royal United Services Institute, and an associate fellow in Euro-Atlantic geopolitics at the Council on Geostrategy.

Mark Lazarevich Gallay was a Soviet test pilot, World War II veteran, and Hero of the Soviet Union.

Mark Gimenez is an author and lawyer from Texas. He specializes in the thriller genre writing, especially legal thrillers. His first novel, The Color of Law, was a New York Times bestseller. He also runs his own solo law practice.

Mark Girouard was a British architectural historian. He was an authority on the country house, and Elizabethan and Victorian architecture.

Mark Goldblatt is an Academy Award-nominated American film editor and film director and president emeritus of the American Cinema Editors.

Mark Gottdiener was a professor of sociology at University at Buffalo, specializing in urban sociology. He is now Professor Emeritus.

Mark Greaney is an Irish musician. He is best known as the singer and guitarist in the alternative rock band JJ72, which he fronted from 1996 until 2006. He was later the frontman of Concerto for Constantine and describes himself as "the perpetual writer of a solo record". Greaney is the head of education at the British and Irish Modern Music Institute.

Mark Eugene Gruenwald was an American comic book writer, editor, and occasional penciler known for his long association with Marvel Comics.