William Christopher (October 20, 1932 – December 31, 2016) was an American actor, best known for playing Father Mulcahy on the television series M*A*S*H and Private Lester Hummel on Gomer Pyle, U.S.M.C.
Christopher appeared in various television series, including Murder, She Wrote and Hogan's Heroes. In 1998 he guest-starred in an episode of Mad About You. He also remained active in the theater, including a tour of the United States in the mid 1990s with Jamie Farr performing Neil Simon's The Odd Couple on stage. In 2008–09, he toured with Church Basement Ladies.
Christopher died at his home on December 31, 2016, in Pasadena, California. According to his son, John Christopher, the 84-year old actor died as the result of small-cell carcinoma.