William Mapother
Actor · Writer · Co-Executive Producer
Born Apr 17, 1965 · Louisville, Kentucky, USA
Active 1989–present
William Reibert Mapother Jr. (/ˈmeɪpɒθər/; born April 17, 1965) is an American actor, known for his role as Ethan Rom on the television series Lost and starring in the film In the Bedroom. He is also known for the film Another Earth.
Filmography
Suits LA (2025) — Greg FisherThe Leader (2026) — Reverend ApplewhiteThe Mentalist (2008) — Richard HaibachAmerican Horror Story (2011) — DriverCriminal Minds (2005) — Ian CorbinLost (2004) — Ethan RomGrimm (2011) — Dwight EleazerMinority Report (2002) — Hotel ClerkLaw & Order: Special Victims Unit (1999) — Luke EdmundsMagnolia (1999) — WDKK Show Director's AssistantThe Blacklist (2013) — BillI Origins (2014) — Darryl MackenzieSupergirl (2015) — Dr. Rudy Jones / ParasiteCastle (2009) — Carl MatthewsMad Men (2007) — Randall WalshNCIS (2003) — Kyle GraysonHawaii Five-0 (2010) — Eric PorterVanilla Sky (2001) — Clubgoer (uncredited)Constantine (2014) — Jacob ShawCSI: Miami (2002) — Pete Keller9-1-1: Lone Star (2020) — Bruce AckermanCSI: Crime Scene Investigation (2000) — Douglas SampsonMission: Impossible II (2000) — WallisJustified (2010) — Delroy Baker