Jim Broadbent
Ebrose is an archmaester of the Citadel. Horace Slughorn is a professor at Hogwarts.
Michelle Fairley
Catelyn Stark is the wife of Eddard Stark, the Lady of Winterfell. Mrs. Granger is the mother of Hermione Granger.
Sally Mortemore
An inhabitant of Braavos. Irma Pince is the head of the Hogwarts library.
Freddie Stroma
Dickon Tarly is the second son of Lord Randyll Tarly (season 6). Cormac McLaggen is a Gryffindor student.
Bronson Webb
Will is The Night Watch scout. Pike is a Slytherin student.
David Bradley
Walder Frey is the head of House Frey, the Lord of the Crossing. Argus Filch is the caretaker of Hogwarts, a squib.
Nicholas Blane
The Spice King is a resident of the city of Qarth and a member of the Thirteen. Bob is an employee of the Ministry of Magic.
Ralph Ineson
Dagmer Cleftjaw is a noted ironborn reaver in the service of House Greyjoy. Amycus Carrow is a Dark wizard, brother of Alecto Carrow and a Death Eater.
Edward Tudor-Pole
Protestor is an unnamed man from the King’s Landing. Borgin is a wizard and the co-owner of Borgin and Burkes, a shop in Knockturn Alley.
Ciarán Hinds
Mance Rayder is the leader of the Free Folk, holding the title of “King-Beyond-the-Wall.” Aberforth Dumbledore is the younger brother of Albus Dumbledore.
Natalia Tena
Osha is a woman of the Free Folk (or “wildling”), in service to House Stark of Winterfell. Nymphadora Tonks is an Order of the Phoenix member.
Julian Glover
Pycelle is the Grand Maester for multiple kings and a member of the small council. Aragog is a spider, an Acromantula, owned by Rubeus Hagrid.