Mark David Duplass (born December 7, 1976) is an American film director, writer, actor and musician.
He played the role of Pete Eckhart in the FX television series, The League, from 2009 to 2015.
Duplass is the brother of filmmaker Jay Duplass, and together the brothers started the film production company Duplass Brothers Productions, and have directed films such as The Puffy Chair (2005), Baghead (2008), Jeff, Who Lives at Home (2011), and The Do-Deca-Pentathlon (2012).
He co-wrote Creep (2014) and appeared in the film as Josef.
In 2019, Duplass wrote and starred in the Netflix comedy film, Paddleton.