William Christopher (born October 20, 1932) is an American actor who is 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 attended New Trier High School in Winnetka, Illinois, and graduated from Wesleyan University in Middletown, Connecticut, with a B.A. in drama. He also participated in fencing, soccer, and the glee club. During his school days, Christopher met his future wife on a blind date, with whom he would eventually have two sons, John and Ned.
Christopher appeared in a variety of regional productions, and eventually a number of off-Broadway productions, such as The Hostage at One Sheridan Square. His Broadway debut came in Beyond the Fringe, a British revue.