Shortly after he moved to London and began to act in various feature films such as “The Lonely Passion of Judith Hearne“(1987) or”The Courier “ (1988); in addition to other works in series and telefilms.
His jump to popularity came, however, towards the end of the 90’s, with his role as Stuart alan jones in the controversial and famous series “Queer as Folk“, for which he received a nomination to the British Academy Television Award, in the year 2000.
Another important role in his television career was that of Thomas ‘Tommy’ Carcetti in the seie “The wire (Bass listening)“, a character that he played over 35 episodes between 2004 and 2008. Then he was John bloom on “Identity“and most recently she starred in the Irish drama series”Love / Hate“.
At the moment Gillen works in the new production of the chain HBO, the medieval epic series, “game of Thrones“, whose premiere is scheduled for April 2011, and in which she plays the role of Petyr “Littlefinger” Baelish.
In his personal life he is divorced from the mother of his two children, Olivia O Flanagan.