Segal's film debut came in "The Young Doctors" (1961), which he followed with small roles in "Act One" (1963) and the "Young Doctors" sequel, "The New Interns" (1964). He raised his profile with an intense turn in the offbeat, confusing "Invitation to a Gunfighter" (also 1964) and attracted more attention as a distraught newlywed in Stanley Kramer's "Ship of Fools" (1965), but it was the World War II POW tale "King Rat" (also 1965) that provided his real breakthrough as the anti-hero con man who effectively manipulates the meager goods and characters of his fellow prisoners, most of whom have higher military rank. He also acted in New York stage productions of Paddy Chayefsky's "Gideon" (1961), "Rattle of a Simple Man" (1963) and "The Knack" (1964), which marked his first association with director Mike Nichols, who would direct Segal in his Oscar-nominated supporting turn in "Who's Afraid of Virginia Woolf?" (1966), adapted by Ernest Lehman from the Edward Albee play.

Firmly ensconced on the A-list, Segal displayed his range in a wide variety of roles. In "The Quiller Memorandum" (also 1966), an atypical spy pic, he went through the entire action without even using a gun, his air of detachment underlining a secret agent's loneliness and lack of relaxation. A gangster in "The St. Valentine's Day Massacre" (1967), he co-starred in Sidney Lumet's proto-"Big Chill" comedy "Bye, Bye, Braverman", hunted down a misogynistic Rod Steiger in "No Way to Treat a Lady" (both 1968) and played a beleaguered Jewish son in Carl Reiner's cult comedy classic "Where's Poppa?" (1970). Segal stretched himself that year as a romantic leading man opposite Eva Marie Saint in "Loving" and Barbra Streisand in "The Owl and the Pussycat" (which reteamed him with screenwriter Buck Henry) and similarly courted Glenda Jackson in "A Touch of Class" (1973) and Goldie Hawn in "The Duchess and the Dirtwater Fox" (1976), though he refused to accept that his wife had walked out on him as "Blume in Love" (1973). He also showed his flair for caper comedies, teaming with Robert Redford as dashing thieves in "The Hot Rock" (1972), parodying Sam Spade in "The Black Bird" (1975) and robbing banks with Jane Fonda in "Fun with Dick and Jane" (also 1976).

Cary Grant had once told Segal that an acting career was like a trolley. You start at the front, but gradually get pushed to the back. At that point you fall off the car, hopefully reinvent yourself and climb back on. At the time he could not imagine plummeting from the lofty heights, but Grant's words proved prophetic as the quality of his film roles declined. After the slick comedy whodunit "Who Is Killing the Great Chefs of Europe?" (1978), it was strictly downhill with disappointments like "Lost and Found" (1979, a failed attempt to repackage the successful chemistry between Segal and Glenda Jackson), the silly racial comedy "Carbon Copy" (1981) and Burt Reynolds' "Stick" (1985). With his career floundering, Segal turned to TV, which had provided him with quality dramatic vehicles in the past. He had played Biff in "Death of a Salesman" (CBS, 1966), escaped convict Glen Griffin in "The Desperate Hours" (ABC, 1967) and George in "Of Mice and Men" (ABC, 1968) before becoming too hot to trouble with the small screen. Now HBO's "The Deadly Game" (1982) and the CBS-TV movies "Trackdown: Finding the Goodbar Killer" (1983), "The Zany Adventures of Robin Hood" (1984), "Not My Kid" (1985) and "Many Happy Returns" (1986) proved the perfect tonic as he sought to reclaim his seat on the trolley.

Segal's feature luck improved with a role as Kirstie Alley's father in the hit "Look Who's Talking" (1989) and its sequel "Look Who's Talking Now" (1993). Having reinvented himself as a supporting player, he delivered equally impressive turns as Bette Midler's uncle in "For the Boys" (1991), a Vietnam veteran in "Me, Myself and I" (1992) and a sleazy TV executive seduced by Nicole Kidman in Gus Van Sant's "To Die For" (1995). Yes, he had fallen off that trolley car and landed on the street, but he had climbed back aboard as attested to by his four 1996 pictures, which saw him portray Eric Roberts' father in "It's My Party", Ben Stiller's adoptive father in "Flirting With Disaster" and Matthew Broderick's father in "The Cable Guy", not to mention appearing with Streisand in "The Mirror Has Two Faces". He did not forsake the small screen, however, essaying Ann-Marget's love interest in "Following Her Heart" (NBC, 1994), mirroring middle-America's disbelief at a father's naivete about his daughter's crimes in "The Good Doctor: The Paul Fleiss Story" (CBS, 1996) and portraying Harry Houdini's manager Martin Beck in "Houdini" (TNT, 1998), among other TV-movies.

It was during the 90s that Segal finally enjoyed his first series success after the failures of "Take Five" (CBS, 1987) and "Murphy's Law" (ABC, 1988-89). Though he received limited exposure in the syndicated "High Tide" (1994-97) and as the voice of Dr. Benton Quest in "The Real Adventures of Jonny Quest" (TNT, TBS, Cartoon Network), he really struck pay dirt as the magazine-owning father of Laura San Giacomo in the NBC sitcom "Just Shoot Me" (1997- ), as well as briefly playing a recurring part as Tea Leoni's father (and Mary Tyler Moore's husband) on NBC's "The Naked Truth" in 1997. He also returned to the Broadway stage for the first time since portraying John Lithgow's greedy fight manager in the 1985 production of "Requiem for a Heavyweight", based on the classic 50s teleplay by Rod Serling. This time he starred with Wayne Knight and old friend Buck Henry in the long-running, Tony-winning "Art" (1999). Segal still plays the banjo, and his group, The Beverly Hills Unlisted Jazz Band, has performed at Carnegie Hall, among other venues.