His screen career began in the 1950s. Windom appeared in various TV series, including
Omnibus and
Robert Montgomery Presents. He continued guest-starring in series during the 1960s including playing The Major in "
Five Characters in Search of an Exit", a 1961 episode of
The Twilight Zone; Windom considered this guest appearance as his West Coast television debut. He later reported that
Richard Widmark was originally offered the role, but when Widmark learned that the pay was only to be $1,000, he turned it down. Actress
Susan Harrison, who played the Ballerina, got first billing, while Windom got second. His first leading role came in the sitcom ''
The Farmer's Daughter'' (1963–1966), a series based on the 1947 film about a young Minnesota woman (played by
Inger Stevens) who became the housekeeper for a widowed congressman (Windom). It ran for three seasons. Windom's first role in film was alongside
Gregory Peck in the
Oscar-winning movie
To Kill a Mockingbird (1962); he played Horace Gilmer, the prosecutor of Tom Robinson (
Brock Peters). He appeared on
The Donna Reed Show,
Gunsmoke,
Star Trek, Mission: Impossible (four episodes), and
Ironside. In
Star Trek, he played Commodore
Matt Decker, commander of the doomed USS
Constellation, in the 1967 episode "
The Doomsday Machine", a role he reprised nearly 40 years later for
Star Trek: New Voyages. He played a recurring role (three episodes) in "
The Invaders" in 1967. In 1968, Windom guest-starred on
Ironside in the episode "Trip to Hashbury." Also in 1968, Windom starred alongside
Peter Falk and
Gene Barry in the TV movie
Prescription: Murder, the pilot for the TV series
Columbo. He starred in another episode of the series titled "
Short Fuse" in 1972. In 1971 he played a supporting role alongside
Jimmy Stewart,
George Kennedy, and
Kurt Russell in the Columbia production ''
Fools' Parade''. Windom starred with
Frank Sinatra in the film
The Detective (1968), playing a homophobic killer, a role appreciated in
The New York Times. The following year, he had the lead role as cartoonist John Monroe in the sitcom
My World and Welcome to It. Although the series only aired for one season, he won the 1970
Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series. In 1971, Windom guest-starred as a victim of blackmail on
Cannon in the episode "Death Chain". In 1974, he guest-starred as Marklund, a grieving father and kidnapper, on
Chopper One in the episode "The Drop". In 1975, he guest-starred as George Kane, a desperate drug dealer, in the series finale of
Mannix in the episode "Hardball". In 1980, he appeared as Amos Krebbs, the alleged father of Ray Krebbs, on the hit primetime television drama
Dallas on the episode "The Fourth Son". Windom toured the country in a one-man
James Thurber show. Afterward, he filmed the pilot for a new series
Is There a Doctor in the House? with
Rosemary Forsyth that was not picked up by a network. Windom joined
Murder, She Wrote in October 1985 as Dr. Seth Hazlitt. He had previously appeared on the series as a guest star playing another character in April 1985. The producers invited him thereafter to return at the beginning of the second season in a continuing role. Windom briefly left the show in 1990 to work on the first television version of
Parenthood, based on the
1989 film of the same name, playing the role of patriarch Frank Buckman—a role played by
Jason Robards in the film and, later,
Craig T. Nelson in the
second TV version. The show was canceled after 12 episodes and Windom returned to
Murder, She Wrote as a semiregular. Windom appeared in 53 episodes of
Murder, She Wrote, second only to Lansbury. Windom continued to appear in film and TV guest roles during the 1990s and 2000s, including
Sommersby (1993),
Miracle on 34th Street (1994), and
Clint Eastwood's
True Crime (1999), and series including
Ally McBeal (2000) and
The District (2001). His final acting appearance came in the 2005 drama ''Yesterday's Dreams''. ==Personal life==