Ardal O’Hanlon, comedian and actor, is born in Carrickmacross, County Monaghan on October 8, 1965. He plays Father Dougal McGuire in Father Ted, George Sunday/Thermoman in My Hero, and DI Jack Mooney in Death in Paradise.

O’Hanlon is the son of politician and doctor Rory O’Hanlon and Teresa Ward. The episode of Who Do You Think You Are? which airs on October 6, 2008, reveals that his paternal grandfather, Michael O’Hanlon, was a medical student at University College Dublin (UCD) who joined the Irish Republican Army (IRA) during the Irish War of Independence and was a member of Michael Collins‘s squad which assassinated British secret service agents on the morning of Bloody Sunday. Details of his grandfather’s activities survive in UCD Archives, as well as Blackrock College. It also transpires that, on his mother’s side, he is a close relative of Peter Fenelon Collier.

O’Hanlon is schooled in Blackrock College in Dublin and graduates in 1987 from the National Institute for Higher Education, Dublin (now Dublin City University) with a degree in Communications Studies.

Together with Kevin Gildea and Barry Murphy, O’Hanlon founds the International Comedy Cellar, upstairs in the International Bar on Dublin’s South Wicklow Street. Dublin has no comedy scene at the time. As a stand up, he wins the Hackney Empire New Act of the Year competition in 1994. For a time, he is the presenter of The Stand Up Show.

O’Hanlon is spotted by Graham Linehan, who casts him as Father Dougal McGuire in Father Ted (1995–98). In 1995 he receives the Top TV Comedy Newcomer at the British Comedy Awards for this role. In 1995, he appears as Father Dougal in a Channel 4 ident and during Comic Relief on BBC One. This is followed by the award-winning short comedy film Flying Saucer Rock ‘n’ Roll.

O’Hanlon moves into straight acting alongside Emma Fielding and Beth Goddard in the ITV comedy-drama Big Bad World, which airs for two series in summer 1999 and winter 2001. He also plays a minor role in The Butcher Boy and appears in an episode of the original Whose Line is it Anyway?.

In 2000, O’Hanlon stars in the comedy series My Hero, in which he plays a very naive superhero from the planet Ultron. His character juggles world-saving heroics with life in suburbia. He stays in the role until the first episode of series 6 in July 2006 where he is replaced by James Dreyfus during the same episode.

O’Hanlon also provides the voice of the lead character in the three Christmas television cartoon specials of Robbie the Reindeer. He appears in the 2005 BBC One sitcom Blessed, written by Ben Elton. Towards the end of 2005, he plays an eccentric Scottish character, Coconut Tam, in the family-based film, The Adventures of Greyfriars Bobby. Although more commonly on television, he also appears on radio. In 2015 he appears as incompetent angel Smallbone in the sitcom The Best Laid Plans, also on BBC Radio 4.

In 2006, O’Hanlon writes and presents an RTÉ television series called Leagues Apart, which sees him investigate the biggest and most passionate football rivalries in a number of European countries. He follows this with another RTÉ show, So You Want To Be Taoiseach? in 2007. It is a political series where he gives tongue-in-cheek advice on how to go about becoming Taoiseach of Ireland.

O’Hanlon appears in the Doctor Who episode “Gridlock“, broadcast on April 14, 2007, in which he plays a cat-like creature named Thomas Kincade Brannigan. He appears in Series 3 of the TV show Skins, playing Naomi Campbell’s Politics teacher named Kieran. He then goes on to form a relationship with Naomi’s mother, played by Olivia Colman. He plays the lead role in Irish comedy television programme Val Falvey, TD on RTÉ One.

In February 2011, O’Hanlon returns to the Gate Theatre, Dublin starring in the Irish premiere of Christopher Hampton‘s translation of Yasmina Reza’s God of Carnage, alongside Maura Tierney. In 2011, he appears in the comedy panel show Argumental.

O’Hanlon has written a novel, The Talk of the Town, which is published in 1998. The novel is about a teenage boy, Patrick Scully, and his friends.

In February 2015 O’Hanlon officially launches the 2015 Sky Cat Laughs Comedy Festival which takes place in Kilkenny from May 28–June 1. In 2015 he plays the role of Peter the Milkman in the Sky One sitcom After Hours.

On February 2, 2017, it is announced O’Hanlon will play the lead role in the BBC crime drama Death in Paradise taking the role of DI Jack Mooney following Kris Marshall‘s departure the same day.