William Mapother (gebore 17 April 1965) is 'n Amerikaanse akteur. Hy is bekend vir sy rolle in die rolprente In the Bedroom (2001) en Another Earth (2011), en in die televisiereekse Lost (2004) en The Mentalist (2008).
- 2001: In the Bedroom
- 2004: The Grudge
- 2005: The Zodiac
- 2007: Moola
- 2007: Mountaintop Removal
- 2008: The Burrowers
- 2009: Hurt
- 2010: The New Sudan
- 2011: Another Earth
- 2011: A Warrior's Heart
- 2012: Static
- 2013: Underdogs
- 2013: It's Dark Here
- 2015: The Atticus Institute
- 2015: Big Box of Horror
- 2004: Lost
- 2008: The Mentalist
- 2012: Ro
- 2014: Craft Yourself Silly
- 2014: American War Generals
- 2008: Stars of the 2008 Vail Film Festival