Rumor of this bubbled up recently when the actor’s CV showed the role, but Access Hollywood now has the confirmation: British actor Karl Davies is Alton Lannister. Davies is perhaps best-known for his role in the long-running British soap, Emmerdale.
Some discussion, and clips featuring the actor, below.
As readers of the novels know, Alton Lannister is not a character in the books. The common speculation, which sounds right to us, is that Alton is going to take over the role of a character that was in the book. Spoilers follow:
Our guess is that he’s basically taking over the role of Cleos Frey, the half-Lannister grandson of Lord Walder who, with his father Ser Emmon, fought on the Lannister side as part of another example of Frey duplicity with Lord Walder having a foot in each camp. Why replace Cleos with a pure Lannister? We can only think that this is just part of keeping the story simpler—this detail about the Freys is telling, but it’s also about a family that is not as important or central to the narrative as the Starks and the Lannisters. We would have preferred he remained Cleos, because it does shade things nicely, but we’ll have to wait and see for how it plays out.
As to Davies, here’s a clip of the actor in the British series Kingdom, a series which starred Stephen Fry in the eponymous role as a solicitor, with Davies playing a trainee: