You might not know Dean-Charles Chapman by his real name, so let's just say this:
BILLY ELLIOTT is joining Game of Thrones!!
Dean was an original member of the Billy Elliot London cast, and then ended up taking over the lead in 2009, sticking around until 2011. He’ll be appearing in the GoT episode directed by David Benioff and D.B. Weiss, which is episode 3!
We HAVE to assume it's a talking role, we mean, people know who he is. The source speculates like this: