Dominic aspired to become an actor from an early age; following his second year at Aquinas, Dominic participated in school plays such as Oliver Twist, A Christmas Carol, and Bugsy Malone. Some of his favorite musicians are the Beatles, Radiohead, Coldplay, Interpol, and the Smiths. Dominic has said that John Lennon is his personal idol: he once ran from Paul Mc Cartney at an Oscar party out of fear of having a potentially disappointing encounter with "the closest thing to what I see as a deity", and he has a tattoo on his arm of a line from the Lennon song "Strawberry Fields Forever", reading "Living is easy, with eyes closed".
(This tattoo is visible on Charlie's arm in Lost as well.) According to a May 11, 2007 Podcast, some of Dominic's other current favorite musicians are Imogen Heap, Keane, Kasabian, Thom Yorke, and Corinne Bailey Rae.
Outside of Lost, he is well-known for playing the hobbit Merry in the film adaptation of The Lord of the Rings.
Wanting to avoid being typecast, Dominic expressed a desire "to play someone different, a nasty and evil character". Through his role in The Lord of the Rings, Dominic was noticed and picked up for Lost.Before that, he became known in England for his role in the British television drama Hetty Wainthropp Investigates (1996).Monaghan was born in Berlin, West Germany, to British parents Maureen, a nurse, and Austin Monaghan, a science teacher.In Atomica, Habel plays Abby Dixon, a safety inspector who is sent to fix the communications network at a remote nuclear power plant isolated in the desert."Once inside the facility, mysterious clues and strange behavior cause Abby to have doubts about the sanity and, perhaps, identities of the two employees onsite;" the two employees being Monaghan and Sizemore.