William Smithers made his Broadway debut as Tybalt in the Dwight Deere Wiman production of Shakespeare's Romeo and Juliet, starring Olivia de Havilland. For his performance he received a Theatre World Award as one of the "Promising Personalities of the Year." His other Broadway plays include: Anouilh's Legend of Lovers, Carson McCullers' Square Root of Wonderful, Calder Willingham's End as a Man, O'Casey's Shadow of a Gunman, and Terence Rattigan's Man and Boy (which he performed in London and in New York). As Treplev in Checkov's The Sea Gull, he received an Obie Award for the Best Performance of the Year by an Actor in an Off-Broadway Play. Also Off-Broadway, he played leading roles in Frank Gilroy's Who'll Save the Plowboy? (Obie Award for Best Off-Broadway Play of the Year) and in George Bellak's The Troublemakers. As part of an international good-will theatrical tour sponsored by the US State Department, Smithers toured throughout South and Central America playing Tom in Tennessee Williams' The Glass Menagerie with Helen Hayes.
In 1952 Mr. Smithers was accepted as a lifetime member of the Actors Studio. He regards the influence of its Artistic Director Lee Strasberg as a key element in his work as actor and director. He has led both acting and directing sessions at the Los Angeles branch of the Actor's Studio; and at The Studio he directed productions of the new plays The Beer-Can Tree, Bob, and Suzanne: A Matter of Sunlight.
In 1965, Mr. Smithers accepted an invitation to play the recurring role of textile-mill executive David Schuster in the popular television series, Peyton Place. Altogether, has appeared or guest-starred in nearly 400 television dramatic programs, including the television series Executive Suite (Anderson Galt); the TV daytime serial The Guiding Light (financier Stanley Norris); and the TV movies Where the Ladies Go, Call to Danger, The Neon Ceiling, Brotherhood of the Bell, The Monk, The Return of Frank Cannon, etc. He has guest-starred in Star Trek, Walker, Texas Ranger, Hunter, Sledge Hammer, The Scarecrow and Mrs. King, Quincy, Doctors' Private Lives, Julie Farr, M.D, Lucan, Amazing Spiderman, Streets of San Francisco, The Rookies, Name of the Game, Barnaby Jones, Hawkins, The Six-Million-Dollar Man, Lawman, Most Wanted, Marcus Welby, M.D, Hawaii Five-O, Owen Marshall, Ironside, F.B.I, Mission: Impossible, Mod Squad, It Takes a Thief, Cade's County, Mannix, The Invaders, Tarzan, Judd for the Defense, Jerico, Felony Squad, Voyage to the Bottom of the Sea, The Road West, Shane, The Invaders, Combat, and The Defenders, among many others. In the 1980's he was perhaps best known for his many appearances as Jeremy Wendell -- J. R. Ewing's archrival -- in the popular television series Dallas.
Mr. Smithers feature films include Attack!, Papillon, Scorpio, Trouble Man, Death Sport, and By Any Other Name.
Mr. Smithers also directed "The Method," an instructional DVD featuring his wife, acting teacher Loraine Hull Smithers.