- Prior to becoming a professional filmmaker and actor, he was the keyboardist and lead singer in the three-piece rock band Volcano, I'm Still Excited!!
- Known as one of the forefathers of Mumblecore, a genre of independent films characterized by its use of small budgets, improv-style acting and true-to-life dialogue.
- Frequently collaborates with his older brother, Jay, who is a renowned screenwriter and film director in his own right.
- Cowrote (with his brother, Jay) and starred in his feature-film debut, The Puffy Chair, which premiered at the Sundance Film Festival in January 2005 and went on to win a Feature Films Audience Award at the 2005 SXSW Film Festival.
- 2006, Independent Spirit Awards — John Cassavetes Award: Nominee
- Cindy Duplass — Mother
- Ora Duplass — Daughter
- Molly Duplass — Daughter
- Larry Duplass — Father
- Jay Duplass — Brother
- Katie Aselton — Wife
- Attended University of Texas, Austin, TX; attended City University of New York, City College, New York, NY
Season 2, Episode 124
- Birth Name: Mark David Duplass
- Birth Place: New Orleans, LA
- Birthday: December 7, 1976, Sagittarius
- Profession: Producer, Screenwriter, Actor, Director