William Tannen (November 17, 1911 – December 2, 1976)^[1] was an American actor originally from New York City.

Tannen was the son of actor Julius Tannen.^[2] William Tannen became active in drama — both acting and writing — while a student at Lawrenceville School.^[3] He made his stage debut in a production of The Honor of the Family with the National Theatre troupe in Washington, D.C.^[4]

During the 1930s and 1940s, he was a Metro-Goldwyn-Mayer contract player. Among his earliest assignments were three appearances as the anonymous "MGM crime reporter" in the studio's Crime Does Not Pay short subjects. Tannen then advanced to membership in the studio's stock company, taking incidental roles in dozens of MGM's feature films. After the studio reduced its personnel in 1948, Tannen began freelancing at other studios but continued to receive assignments at MGM for the next decade. Television viewers of the 1950s recognized Tannen from his role of Deputy Hal Norton in 56 episodes of the ABC/Desilu western television series, The Life and Legend of Wyatt Earp (1956-58)