Merlin
Colin Morgan
Arthur Pendragon
Bradley James
Gauis
Richard Wilson
Gwen
Angel Coulby
Guest Star
Mackenzie Crook
Uther Pendragon
Anthony Head
The Great Dragon (voice)
John Hurt
Morgana
Katherine Elizabeth McGrath
Gaius
Richard Wilson
Morgana
Katie McGrath
Guest Star
Rupert Young
Guest Star
Jonathan Bryan
Guest Star
Richard Ridings
Guest Star
David Schofield
Guest Star
Sarah Parish
Guest Star
Justin Avoth
Guest Star
Victoria Finney
Guest Star
Fintan McKeown
Guest Star
Simon Nehan
Guest Star
Emilia Fox
Guest Star
Jack Sandle
Guest Star
Kevin Eldon
Guest Star
Adam Godley
Guest Star
Jem Wall
Guest Star
Michael Nardone
Guest Star
Joseph Mawle
Guest Star
Laura Donnelly
Guest Star
Jonathan Coyne
Guest Star
Beth Cordingly
Agravaine de Bois
Nathaniel Parker
Guest Star
Charles Dance
Guest Star
Michael Ballard
Geoffrey of Monmouth
Michael Cronin
Guest Star
Mark Lewis Jones
Guest Star
Alice Patten
Guest Star
Alexander Delamere
Guest Star
Emily Beecham
Guest Star
Katie Foster-Barnes
Sir Geraint
Luke Neal
Guest Star
Colin Salmon
Guest Star
Adrian Lester
Guest Star
Rhys Rusbatch
Guest Star
James Cosmo
Guest Star
Amanda Fairbank-Hynes
Cenred
Tom Ellis
Guest Star
Georgia Moffett
Guest Star
Asa Butterfield
Guest Star
John Lynch
Guest Star
Samara MacLaren
Guest Star
Chris McGill
Guest Star
Brian Peck
Guest Star
Santiago Cabrera
Guest Star
Alex Price
Gwaine
Eoin Macken
Guest Star
Jai Armstrong
Hunith
Caroline Faber
Guest Star
Mike Goodenough
Guest Star
David Sterne
Elyan
Tomiwa Edun
Iseldir
Trevor Sellers
Helios
Terence Maynard
Audrey
Zee Asha
Sefa
Sophie Rundle