William Louis Hudson Jr. (born October 17, 1949) is an American musician and actor. He was a vocalist in The Hudson Brothers, a band he formed in 1965 with his two younger brothers, Brett and Mark. He later had a brief acting career, appearing in supporting roles in Zero to Sixty (1978), Hysterical (1983), and Big Shots (1987). He also appeared in a recurring guest role on the series Doogie Howser, M.D..