"Hodor is a real guy named Kristian Nairn and he's a famous DJ in Ireland with a bunch of tiny stars tattooed on his forehead! It seems that Kristian was a DJ long before he ever graced the back roads of Westeros with little Bran Stark on his back. In addition to holding a residency at a spot called Kremlin, an enormous gay club in Belfast, Kristian has toured all over the world with the likes of Calvin Harris, Mylo and the Scissor Sisters. Music is actually his main thing, and he landed the role of wonderful Hodor without having previously done much acting. Which, if you have seen Hodor emote, is basically impossible to imagine."
-Liana Maeby @ Hitfix
Belfast-born Dublin-based Kristian Nairn, Hodor in Game Of Thrones (above), getting medieval on the decks in an unnamed Dublin venue.
Here is one of his remixes:
He was apparently a drag queen named DJ Revlonn too: http://website.lineone.net/~toby-ni/kremlin/features/archive/oscars/revlon.jpg