He first became known for his role as bartender Woody Boyd on the NBC sitcom Cheers (1985–1993), for which he won a Primetime Emmy Award for Outstanding Supporting Actor in a Comedy Series from five nominations.

He reunited with Wesley Snipes (who also had debuted in Wildcats) in the box-office hit White Men Can't Jump (1992) and the action movie Money Train (1995).

In 1993, Harrelson starred opposite Robert Redford and Demi Moore in the drama Indecent Proposal, which was a box office success, earning a worldwide total of over $265,000,000.

In 1998, Harrelson starred in the thriller Palmetto and played Sergeant Keck in the Terrence Malick directed war film The Thin Red Line, which received nominations for seven Academy Awards in 1999 including for Best Picture.

He followed next in Roundabout's Broadway revival of the N. Richard Nash play The Rainmaker in 2000, Sam Shepard's The Late Henry Moss in 2001, John Kolvenbach's On an Average Day opposite Kyle MacLachlan in London's West End in the fall of 2002, and in the summer of 2003, Harrelson directed the Toronto premiere of Kenneth Lonergan's This is Our Youth at the Berkley Street Theater.

In the winter of 2005–2006 Harrelson returned to London's West End, starring in Tennessee Williams' Night of the Iguana at the Lyric Theater.

Harrelson directed Bullet for Adolf (a play he wrote with Frankie Hyman) at the esteemed Hart House Theatre in Toronto, Ontario, which ran from April 21 to May 7, 2011.

Bullet for Adolf opened Off-Broadway (New World Stages) with previews beginning July 19, 2012, and closed on September 30, 2012, canceling its announced extension through October 21.

Harrelson also won a Screen Actors Guild Award for Best Cast, along with Tommy Lee Jones, Javier Bardem, Josh Brolin, and Kelly Macdonald.

In 2008, Harrelson appeared in several films, among them the Will Ferrell basketball comedy Semi-Pro and the stark Will Smith drama Seven Pounds as a blind vegan meat salesman named Ezra Turner.

Also that same year, Harrelson co-starred in the horror comedy Zombieland, followed by Roland Emmerich's 2012, where he played Charlie Frost, a man who warns of the end of the world.

[citation needed] Despite being initially unaware of exactly from where his kick had to be taken, Harrelson scored to win the game for "The Rest of the World" team, beating England for the first time since the tournament began.

Harrelson narrated the 2011 film ETHOS, which explores the idea of a self-destructing modern society, governed by unequal power and failed democratic ideals.

In 2012, he had a leading role in the acclaimed HBO television film Game Change as republican strategist Steve Schmidt working for the 2008 Presidential campaign for John McCain and Sarah Palin.

[18] The AMA turned into a PR disaster when Harrelson failed to make meaningful responses to any questions and soon specifically refused to respond to anything not directly related to the then-upcoming worldwide release of the crime drama Rampart (2011), in which he starred and received a nomination for the Independent Spirit Award for Best Male Lead.

[19][20][21] Harrelson returned to television in 2014, starring along with Matthew McConaughey in the first season of the HBO crime series True Detective, where he played Marty Hart, a Louisiana cop investigating murders that took place over a timespan of 17 years.

He and McConaughey received nominations for the Primetime Emmy Award for Outstanding Lead Actor in a Drama Series losing to Bryan Cranston for the final season of Breaking Bad.

'[22] In 2016, Harrelson announced that he would direct, write, produce, and star in a film, Lost in London, which was shot as a single take and premiered live on January 19, 2017.

Starting in 2019, Harrelson made numerous appearances portraying Joe Biden on Saturday Night Live, before being replaced by Jim Carrey.

[35] In March 2021, he is set to portray Felix Kersten in The Man with the Miraculous Hands, the feature film adaptation of Joseph Kessel's 1960 novel of the same title.

[36] Harrelson starred in the HBO political limited series White House Plumbers (2023) where he portrayed intelligence officer E. Howard Hunt.

The union was not intended to be serious, and the two had planned to divorce the following day, but the storefront marriage/divorce parlor was closed when they returned to it and they remained married for another ten months.

In November 2018, he attended the first game of the World Chess Championship in London, played between Norwegian champion Magnus Carlsen and American contender Fabiano Caruana.

Harrelson had arrived in the county with his attorney, former Kentucky Governor Louie B. Nunn, an agent and a camera crew from CNN.

Los Angeles prosecutors declined to press charges against the actor, but Levine filed a suit that summer asking for $2.5 million in damages.

[75] PICNIC describes its annual festival as "three intensive days [when] we mix creativity, science, technology, media, and business to explore new solutions in the spirit of co-creation".

[82] In 2002, Harrelson wrote an article in the British newspaper The Guardian condemning President George W. Bush's preparation for a US invasion of Iraq as a "racist and imperialist war".

In 2013, Harrelson condemned President Barack Obama for failing to withdraw U.S. troops from Afghanistan, negatively comparing him to Richard Nixon.

On television, his breakthrough role as bartender Woody Boyd earned him five Emmy nominations in the category of Outstanding Supporting Actor in a Comedy Series, with one win.

Aside from his numerous successes in the industry, other credits include North Country (2005), No Country for Old Men (2007), 2012, Zombieland (both 2009), Now You See Me (2013) and its 2016 sequel, The Hunger Games film series (2012–2015), The Edge of Seventeen, LBJ (both 2016), The Glass Castle (2017) and Kate (2021), Harrelson has also starred in critically panned films, with his role in 1993's Indecent Proposal winning him the Golden Raspberry Award for Worst Supporting Actor in 1994.