Marcus Dunstan (born April 14, 1978) is an American screenplay writer and director who, along with Patrick Melton, wrote screenplay for the film Feast, which was the winner of Season Three of the filmmaking competition reality TV series Project Greenlight. Dunstan has since written the screenplays for Feast, Feast 2: Sloppy Seconds, Feast 3: The Happy Finish, The Collector, Saw IV, Saw V, Saw VI, and Saw 3D, and in some cases, making cameo appearances in those films as well.