Colin James Farrell (/ˈfærəl/; born 31 May 1976) is an Irish actor. A leading man in blockbusters and independent films since the 2000s, he has received various accolades, including three Golden Globe Awards, one SAG Award, and nominations for an Academy Award and an Emmy Award. The Irish Times named him Ireland's fifth-greatest film actor in 2020, and Time magazine named him one of the 100 most influential people in the world in 2023.

Farrell began acting in the BBC drama series Ballykissangel (1998) and made his (first credited) film debut in the drama The War Zone (1999). His first lead film role was in the war drama Tigerland (2000), and he made his breakthrough in Steven Spielberg's science fiction film Minority Report (2002). He took on high-profile roles such as Bullseye in Daredevil (2003) and as Alexander the Great in Alexander (2004), with further starring roles in Phone Booth (2002), The Recruit (2003), S.W.A.T. (2003), and Miami Vice (2006).

Farrell earned acclaim for playing a novice hitman in his first film with frequent collaborator Martin McDonagh, the dark comedy In Bruges (2008), winning a Golden Globe Award. He went on to play a variety of leading and character roles in the comedy Horrible Bosses (2011), the science fiction film Total Recall (2012), the drama Saving Mr. Banks (2013), the dark comedies Seven Psychopaths (2012) and The Lobster (2015), the thrillers The Killing of a Sacred Deer (2017), The Beguiled (2017) and Widows (2018), and the fantasy films Fantastic Beasts and Where to Find Them (2016) and Dumbo (2019). He also starred in the second season of HBO's thriller series True Detective (2015).

Farrell played Oz Cobb / Penguin in the superhero film The Batman (2022) and the HBO series The Penguin (2024), winning a Golden Globe award for the latter. In 2022, he gained acclaim for his roles in the science fiction drama After Yang, the survival film Thirteen Lives, and McDonagh's drama The Banshees of Inisherin. For playing a naïve Irishman in the lattermost, he won the Volpi Cup for Best Actor and another Golden Globe, in addition to a nomination for the Academy Award for Best Actor.

Colin James Farrell was born in Castleknock, a western suburb of Dublin on 31 May 1976, to Rita (née Monaghan) and Eamon Farrell. His father played football for Shamrock Rovers FC and ran a health food shop. Farrell played for Castleknock Celtic FC, and the team was managed by his father. Farrell's uncle, Tommy Farrell, also played for Shamrock Rovers. Farrell has an older brother named Eamon, and two sisters, Catherine and Claudine (the latter now works as his personal assistant). Farrell grew up Catholic and went to St Brigid's National School, Castleknock, followed by the exclusive^{[citation needed]} all-boys private school Castleknock College, and then Gormanston College in Gormanston Castle in County Meath. He unsuccessfully auditioned for the boy band Boyzone around that time.

Farrell was inspired to try acting when Henry Thomas's performance in E.T. the Extra-Terrestrial (1982) moved him to tears. With his brother's encouragement, he attended the Gaiety School of Acting, but dropped out when he was cast as Danny Byrne in the BBC drama Ballykissangel. While traveling in Sydney at the age of 18, Farrell became a suspect in an attempted murder case. The police sketch looked remarkably like him and he had even described blacking out during the night in question; his only alibi was that a friend journaled that the two had been taking MDMA on the other side of town that night.

Farrell had roles in television shows and films, including Ballykissangel and Falling for a Dancer in 1998 and 1999. He made his feature film debut in English actor Tim Roth's directorial debut, The War Zone, a drama about child sexual abuse, starring Ray Winstone and Tilda Swinton as parents of a girl Farrell's character (Nick) dates. Farrell appeared in Ordinary Decent Criminal with Kevin Spacey and Linda Fiorentino, a film loosely based on the life of Martin Cahill. In 2000, Farrell was cast in the lead role of Private Roland Bozz in Tigerland, directed by Joel Schumacher. Farrell reportedly got the part on the basis of his charm. Emanuel Levy of Variety said that Farrell "shines as the subversive yet basically decent lad whose cynicism may be the only sane reaction to a situation". Michael Holden of The Guardian wrote that Farrell was "too much the hero" to fit the classic rebel archetype properly, but he still delivered a good performance. Tigerland earned $139,500.

Farrell's next American films, American Outlaws (2001) and Hart's War (2002), were not commercially successful. His 2002–2003 films, including Phone Booth, The Recruit and S.W.A.T. (all thrillers, with the former two his first starring roles), were well received by critics and successful at the box office. Of Phone Booth, Roger Ebert wrote that it is "Farrell's to win or lose, since he's onscreen most of the time, and he shows energy and intensity". Philip French of The Guardian praised Farrell's performance. In S.W.A.T., Farrell starred in an ensemble cast including Samuel L. Jackson, Michelle Rodriguez, Olivier Martinez and Jeremy Renner; Renner became a friend. Alan Morrison of Empire wrote, "Farrell can usually be relied upon to bring a spark to the bonfire. That's also true of [this movie]." Elvis Mitchell of the New York Times criticised Farrell's accent, writing that he "employ[ed] a wobbly American accent that makes him sound like an international criminal a step ahead of the authorities". Ebert and The New York Times' A.O. Scott disagreed on Farrell's effectiveness in The Recruit; Ebert noted Farrell's likability, but Scott felt that Farrell "spends his time in a caffeinated frenzy, trying to maintain his leading-man sang-froid while registering panic, stress and confusion". Phone Booth earned $46.6 million, S.W.A.T. $116.9 million and The Recruit $52.8 million at the box office.