He was born on December 8, 1976 in Berlin, but his family often changed their place of residence. So he grew up in places like Düsseldorf, Stuttgart and Münster. Eventually, when the actor was 11, they settled permanently at the English Heaton Moor in Stockport. He attended St Anne’s Roman Catholic High School there, and then continued his education at Aquinas College. There he studied English literature, drama and geography. He was also active in the student theater group. He became interested in cinema at the age of 6, when he first watched Star Wars . His acting career was initially, however, not related to film, but to theater. He has performed at the Manchester Youth Theater, appearing in plays such as Oliver Twist , A Christmas Carol and Bugsy Malone.
He made his screen debut in the BBC series Hetty Wainthropp Investigates, where he appeared as Geoffrey. Shortly thereafter, he appeared in the HBO production of The Sinister Depth, playing the role of a Russian seaman. The role in the Lord of the Rings trilogy was a definite breakthrough for his career . Initially, he competed for the role of the main character, Frodo Baggins, but eventually this role was given to Elijah Wood, and Monaghan was taken by his film friend – Merry Brandybuck. He also appeared in the cult TV series Lost , where he played the role of the former musician and drug addict – Charlie. He also appeared in The Dead Man’s Selling , as Arthur Blake and FlashForward: Tomorrow’s Glimmer, playing Simon Campos. He also appeared in the X-Men production of Genesis: Wolverine as Chris Bradley. He was also involved in Star Wars: Skywalker. A revival where he played Beaumont. Thanks to his achievements, he was awarded two statuettes of the American Guild of Film Actors, and also received 4 nominations, including for Saturn and People’s Choice Awards.