Greg Kinnear made his debut in the 1988 television film ‘What Price Victory.’ The following year, he appeared in the Episode: "Break a Leg, Mom" of the American television series ‘Life Goes On.’ He next appeared in television series and shows such as ‘Mancuso, F.B.I.’ (1990), ‘L.A. Law’ (1991), and ‘Best of the Worst’ (1991). In 1991, he joined the television show ‘Talk Soup’ as a host. He remained a part of the show until 1995. Kinnear made his big-screen debut in the 1994 American superhero comedy parody film ‘Blankman’ directed by Mike Binder. The film was panned by critics and was a box office bomb. In 1995, he starred as ‘David Larrabee’ in the American romantic comedy-drama film ‘Sabrina’ directed by Sydney Pollack. Even though the film received mostly positive reviews, it failed to achieve success at the box office. In 1997, he was seen playing the role of ‘Simon Bishop’ in the American romantic comedy-drama film ‘As Good as It Gets’ directed by James L. Brooks. The film received positive reviews from critics and was a major financial success, grossing over $314.1 million on a budget of $50 million. Kinnear also won several award nominations including the ‘Academy Award,’ ‘Golden Globe Award,’ and ‘Screen Actors Guild Award’ nominations for his performance in the film.
He next starred in films like ‘You've Got Mail’ (1998), ‘Mystery Men’ (1999), ‘What Planet Are You From?’ (2000), ‘Nurse Betty’ (2000), ‘The Gift’ (2000), and ‘Someone like You’ (2001). In 2002, he portrayed Maj. Bruce "Snake" Crandall in the American war film ‘We Were Soldiers’ directed by Randall Wallace. The film received a positive response from critics. The following year, he was seen playing the role of ‘Walter Tenor’ in the American comedy film ‘Stuck on You’ directed by Peter Farrelly and Bobby Farrelly. The film opened to mostly positive reviews from critics. He was next seen playing the role of ‘Paul Duncan’ in the 2004 Canadian-American horror drama-thriller film ‘Godsend.’ The film failed to impress the critics and was a box office disappointment. Kinnear went on to appear in films like ‘The Matador’ (2005), ‘Bad News Bears’ (2005), ‘Invincible’ (2006), ‘Feast of Love’ (2007), ‘Ghost Town’ (2008), ‘Flash of Genius’ (2008), ‘Green Zone’ (2010), ‘Thin Ice’ (2011), ‘I Don't Know How She Does It’ (2011), ‘Stuck in Love’ (2012), and ‘Movie 43’ (2013).
In 2013, he starred as ‘Dr. Richard Riker’ in the American romantic comedy-drama film ‘The English Teacher’ directed by Craig Zisk. The film received a mixed response from critics. That same year, he also appeared in the American satirical comedy film ‘Anchorman 2: The Legend Continues.’ The film received mostly positive reviews and was a box office success. He was next seen in films like ‘Heaven Is for Real’ (2014), ‘Murder of a Cat’ (2014), ‘Little Men’ (2016), ‘Brigsby Bear’ (2017), ‘Brian Banks’ (2018), ‘Frankie’ (2019), ‘The Red Sea Diving Resort’ (2019), and ‘Misbehaviour’ (2020). Kinnear was last seen in the 2021 crime thriller film ‘Crisis’ directed by Nicholas Jarecki. The film opened to mostly positive reviews. He is all set to appear in the upcoming American horror comedy television series ‘Shining Vale’ where he will play the role of ‘Terry.’