Tom Poston, who gained fame playing a series of slow-witted, but appealing everyman characters on television, often acting as a comic foil to Bob Newhart, died April 30, 2007, at his home in Los Angeles. He was 85. Tom Poston's niche in show business was, it seems, carved out at an early stage. He first earned widespread fame on the "The Steve Allen Show" playing, among other comic creations, a doltish man on the street who could not come up with answers to a reporter's simplest questions. He won an Emmy in 1959 for his work on Allen's show.

Blessed with a large, open face and a wide-eyed gaze that communicated gullibility and simple-mindedness, Mr. Poston made a career out of being the endearing/annoying sidekick to smarter characters. Audiences associated him most closely with Newhart. Mr. Poston played Cliff, Bob's intrusive, none-too-bright neighbor on the long-running "Bob Newhart Show" in the 1970s. He also had a regular role on the 1980s sitcom "Newhart," playing ineffective handyman George Utley, one of the various, counter-intuitive Vermonters that bedeviled Newhart's life as a country innkeeper.

Tom Gordon Poston, born Oct. 17, 1921, in Columbus, OH, began his acting career in New York City. He first appeared on Broadway in 1947, filling a small part in Cyrano de Bergerac. He would return to Broadway 12 more times, though he never had much luck in that arena. Among the briefly flickering attractions he acted in were Stockade (1954), The Grand Prize (1955), Goodbye Again (1956), Drink to Me Only (1958), Golden Fleecing (1959) and But, Seriously… (1969).

He had big roles in two unsuccessful musicals. In 1957's Shinbone Alley—based on columnist Don Marquis' "Archy and Mehitabel" stories about the adventures of a typing cockroach and a lovelorn cat—he was standby for Eddie Bracken, who played Archy. The show ran only 49 performances. Four years later, he was Woodrow Truesmith in The Conquering Hero, based on the Preston Sturges film comedy "Hail, the Conquering Hero" about a mopey 4F would-be soldier who returns to his hometown pretending to be a war hero. Moose Charlap wrote the music, Norman Gimbel the lyrics and Larry Gelbart the book. The show ran a mere eight performances.

Mr. Poston found more success on the Broadway stage replacing actors in established comedies like Will Success Spoil Rock Hunter?, Mary, Mary and Forty Carats.

As a young man, Mr. Poston boxed in several hundred amateur fights, according to the New York Times. In the late 1930s, he enrolled at Bethany College in West Virginia, where he studied chemistry. He left college to serve in World War II as a pilot with the Army Air Corps in Europe. When he returned, he attended the American Academy of Dramatic Arts in New York and trained with Sanford Meisner.

Mr. Poston is survived by his wife, actress Suzanne Pleshette. In a union that seemed a tad surreal to television audiences—who knew Pleshette as Bob Newhart's wife on "The Bob Newhart Show," and only a friendly neighbor to Mr. Poston—the two married in 2001. They had actually first met and become romantically involved in 1959, when they co-starred on Broadway in Golden Fleecing. In the intervening decades, each actor married other people. Mr. Poston's marriage to Jean Sullivan lasted from 1955 to 1968 and produced one daughter, Francesca Poston, who also survives him. He then married Kay Hudson twice, first from 1968 to 1975, then from 1980 to her death in 1998. They had two children.