William Mapother

William Reibert Mapother, Jr. (born April 17, 1965) is an American actor who provides the voice of Colonel Hsu in Fallout: New Vegas. He is best known for his role as Ethan Rom on the television series Lost. He is the cousin of Tom Cruise.

Mapother's only prior voice acting experience are two appearances on Robot Chicken, one on WordGirl and "Halo: Reach".