Charlie Hunnam character Arthur
Astrid Bergès-Frisbey character The Mage
Jude Law character Vortigern
Djimon Hounsou character Bedivere
Eric Bana character Uther
Aidan Gillen character Bill
Freddie Fox character Rubio
Craig McGinlay character Percival
Tom Wu character George
Kingsley Ben-Adir character Wet Stick
Neil Maskell character Back Lack
Annabelle Wallis character Maggie
Zac Barker character Young Arthur 2 Yrs
Oliver Barker character Young Arthur 2 Yrs
Geoff Bell character Mischief John
Poppy Delevingne character Igraine
Millie Brady character Catia
Nicola Wren character Lucy
Wil Coban character Brother Blackleg
Bleu Landau character Blue
Jacqui Ainsley character Lady of the Lake
Lorraine Bruce character Syren 1
Georgina Campbell character Kay
Rob Knighton character Mordred
Michael Hadley character Mage King
David Beckham character Trigger
Katie McGrath character Elsa
Alan Turkington character General 1
Peter Ferdinando character Earl of Mercia
Michael McElhatton character Jack's Eye
Mikael Persbrandt character Greybeard
Charlie Rawes character Axeman
James Warren character Mike
Ellie Graham character Maria
Hermione Corfield character Syren 3
Kamil Lemieszewski character Merlin
Eline Powell character Syren 2
Kalle Hennie character Viking
Peter Guinness character Baron 1
Mark Umbers character Baron 2
Adrian Bouchet character Baron 3
Florence Bell character Woman 1
Anna Brooks Beckman character Woman 2
Cordelia Bugeja character Woman 3
Rebecca Calder character Maid 1
Lee Nicholas Harris character Dan Clan Mafia (uncredited)
Gintare Beinoraviciute character Noble (uncredited)
Alice E. Mayer character Noble Girl (uncredited)
Claira Watson Parr character Noblewoman (uncredited)
Alphonso Austin character Slave Labourer (uncredited)
Rudy Barrow character Londinium Fighter (uncredited)
Daniel Stisen character SPAC / Londinum Fighter (uncredited)
Joel Bryant character Londinium Fighter (uncredited)
Dacio Caballero character Fighter (uncredited)
Lucy Chappell character Young Mother (uncredited)
Jamie B. Chambers character Knight (uncredited)
Pedro Caxade character Vortigern's Guard (uncredited)
Nick Cornwall character Clan Head 1 (uncredited)
Steve Barnett character Brothel Punter (uncredited)
Guy Ritchie character Inn Owner