Despite playing the monstrous Joffrey on Game of Thrones (2011), all of his co-stars have described him as one of the nicest and friendliest actors they have ever worked with.
He based his performance as Joffrey in Game Of Thrones (2011- ) on Joaquin Phoenix's performance in Gladiator (2000).
Doesn't like to swear and usually avoids it in rehearsal and does it in the take.
Has said he doesn't plan to continue acting after finishing Game of Thrones (2011).
Gleeson is the founder and artistic director of Collapsing Horse Theatre Company, which is based in Dublin.
Is a student at Trinity College in Dublin.
Is a co-founder of Collapsing Horse, a production company. "Monster/Clock: A Play on Time" was the recent puppet production performed at the Smock Alley Theatre in Dublin, Spring, 2012. He was the puppeteer for the lead character, Toby.
He went to Gonzaga College, a private school in Dublin from 2004-2010.
Is a member of the DU Players.
Croatia, Dubrovnik: Filming Game of Thrones (April 2012)