The youngest of three sons born to a diplomat, Kinnear grew up in various places around the world, including Beirut, Lebanon and Athens, Greece. After attending the University of Arizona, the Indiana-born Kinnear got his start marketing low-budget films before switching gears and stepping in front of the camera. He hosted the TV shows "College Mad House" (syndicated, 1989) and "The Best of the Worst" (Fox, 1991-92) before hitting the big time with "Talk Soup". Kinnear was consequently courted by the powers that be to assume a prominent place in broadcast TV: Fox was allegedly interested in having him replace Chevy Chase in their late night slot; Disney wanted to discuss a possible sitcom and talk show projects; Rob Reiner proposed a syndicated talk show; and CBS reportedly wooed him for the slot after David Letterman.

In 1994, Kinnear opted to replace Bob Costas on the late night interview show, "Later.” NBC obligingly shifted production from NYC to L.A. so as to allow Kinnear to serve double duty on "Later" and "Talk Soup" (until 1994, when John Henson took over as host of "Soup"). The revamped "Later" added a live audience, occasional comedy sketches and an introductory "videologue" in which Kinnear reacted to the day's events.

It was only a matter of time before he film projects were dangled before him. Having briefly worked as an actor in the late 80s and early 90s in such TV-movies as "What Price Victory" (ABC, 1988), "Murder in Mississippi" (NBC, 1990) and "Dillinger" (ABC, 1991) and in guest spots on series ("Life Goes On", "L.A. Law"), often playing journalists, Kinnear made his feature film debut as a talk show host in "Blankman" (1994). But his first big break came when he was tapped to step into the William Holden role in the 1995 Sydney Pollack-directed remake of "Sabrina". In what was considered a no-win proposition (the film suffered in comparison to the 1954 original), Kinnear emerged relatively unscathed, impressing with his sharp turn as the profligate younger son. He was next hired to star as a con man tuned postal worker who answers mail addressed to the Almighty in "Dear God" (1996), but that film also failed to find an audience. Undeterred, Kinnear went on to appear in another failure, cast as the newlywed husband of Lauren Holly in the romantic comedy "A Smile Like Yours" (1997).

The actor bounced back earning strong reviews and accolades, including a Best Supporting Actor Academy Award nomination, for his performance as a gay man who is befriended by a crusty neighbor (Jack Nicholson) in James L Brooks' comedy-drama "As Good as It Gets" (1997). He followed in another supporting turn as Meg Ryan's boyfriend in "You've Got Mail" (1998), an update of 1940's "The Shop Around the Corner" directed by Nora Ephron. Kinnear was next seen as one of the superheroes (Captain Amazing) in "Mystery Men" (1999) and demonstrated his patented smugness as a college professor romancing a student in the aptly named "Loser" (2000). One of his better screen roles was the soap opera lead who finds himself the object of attention of an ardent fan (Renee Zellweger) in "Nurse Betty" (also 2000). He rounded out that busy year portraying the meek lover of a trampy socialite in the neo-Gothic "The Gift.”

In the new millennium, Kinnear once again played something of a rat, essaying a dashing TV producer who unceremoniously dumps his talk-show host lover (Ashley Judd) in the romantic comedy "Someone Like You" (2001). He next was seen in the small screen adaptation of the Pulitzer-winning exploration of marriage, "Dinner With Friends" (HBO, 2001) and in the ensemble of the Vietnam-era drama "We Were Soldiers"(2002). Kinnear landed the lead role in the film "Auto Focus" (2002) playing Bob Crane, the star of "Hogan's Heroes" whose secret life of sexual escapades was discovered after he was found murdered in his apartment. The actor was praised for his performance in the little-seen film; next, despite several favorable reviews, he and Matt Damon were not able to draw a large audience to the Farrelly Brothers comedy "Stuck On You" (2003), in which they played combative conjoined twins. He did, however, enjoy a memorable guest stint on "Friends" in November of 2003, playing the professor who wins back Ross' beautiful girlfriend Charlie--played by another "Talk Soup" host turned actor, Aisha Tyler.

Less promising was his turn in the science-based thriller "Godsend" (2004), playing opposite Rebecca Romijn-Stamos as a couple who raise a clone of their dead child, with chilling results. Next, Kinnear was the voice of Ratchet, a corporate bigwig in a world inhabited by mechanical beings in the CGI-animated “Robots” (2005), then took on the Vic Morrow role of opposing coach in Richard Linklater's remake of the classic kids' baseball film "The Bad News Bears" (2005), playing the role with amped-up smarm instead of Marrow's patriarchal menace. In “The Matador” (2005), Kinnear played an everyman on a business trip in Mexico who befriends an assassin (Pierce Brosnan) going through a midlife crisis. He then led the ensemble cast in “Little Miss Sunshine” (2006), playing a hopelessly optimistic—and annoying—motivational speaker unable to motivate anyone who undertakes a road trip with his dysfunctional family to take his daughter to her beauty pageant. “Little Miss Sunshine” charmed critics after it made a splash at the 2006 Sundance Film Festival, with Kinnear receiving numerous kudos for his strong performance, dubbed by Variety as one of his best. While “Sunshine” was in theaters, Kinnear was seen in the inspirational sports drama, “Invincible” (2006), the true-to-life telling of improbable NFL player Vince Papale, a former part-timer bartender turned special teams star on the Philadelphia Eagles. Kinnear played first year coach Dick Vermeil, who hopes to turn around 11-straight losing seasons by holding open tryouts for Philadelphia locals.