Trivia

Became an American citizen in 2009.

Got his cauliflower ear (the right one) playing rugby.

In The Agency (2001) episode, Thanksgiving (2002), Jason O'Mara's character, "A.B. Stiles", must go undercover, posing as an I.R.A. terrorist.

Despite the fact that O'Mara was born and raised in Dublin, his character is told at the end of the episode, "Do something about that phony Irish accent!".

In addition, in an episode of "Life on Mars" entitled 'All the Young Dudes', his NYC detective character went undercover in the Irish mafia. While undercover he claims to be from Sandycove area of Dublin, which is where O'Mara is really from. As opposed to his appearance on "The Agency" he is told by a fellow cop, "Hey I thought you really were Irish. You're good at accents!" His wife Paige Turco played his love interest in the episode, the sister of the mafia boss.

He has played the role of Bruce Wayne/Batman in six animated films. The only actor to play the role more times is Kevin Conroy.

He received a nomination for Best Supporting Actor at the 2002 Irish Theater Awards for his performance in "Bash", written and directed by Neil LaBute, at the Gate Theater, Dublin.

Has played both a Marvel Comics character and a DC Comics characters. Portrays Jeffrey Mace in "Marvel's Agents of S.H.I.E.L.D." and plays Bruce Wayne/Batman in 6 different DC animated films.

Father, with his now ex-wife Paige Turco, of son David O'Mara, born in 2004.

He has a degree in Drama from Trinity College, Dublin, Ireland.

He also appeared in the multi-award winning production of Harold Pinter's "The Homecoming", with Ian Holm, which played in Dublin, London and at Lincoln Center, New York.

With the story arc of the Framework in "Agents of S.H.I.E.L.D." his character of Jeffrey Mace is living in a virtual reality, as was the case with his character of Sam Tyler in "Life on Mars".

Played Dr. John Ellison on Complications and Dr. Keith Winters on CSI: Miami episode titled Complications.

Brother of Rebecca O'Mara.