Charlie Hunnam

Arthur

Jude Law

Vortigern

Astrid Bergès-Frisbey

The Mage

Eric Bana

Uther Pendragon

Djimon Hounsou

Bedivere

Aidan Gillen

William "Goosefat Bill"

Kingsley Ben-Adir

Tristan "Wet Stick"

Neil Maskell

Back Lack

Craig McGinlay

Percival "Percy"

Tom Wu

"Kung Fu" George

Freddie Fox

Rubio

Mikael Persbrandt

Greybeard

Peter Ferdinando

Earl of Mercia

Geoff Bell

Mischief John

Annabelle Wallis

Maggie

Katie McGrath

Elsa

Lorraine Bruce

Syren 1

Eline Powell

Syren 2

Hermione Corfield

Syren 3

Bleu Landau

Blue

Poppy Delevingne

Igraine

Millie Brady

Catia

Zac Barker

Young Arthur 2 Yrs

Oliver Barker

Young Arthur 2 Yrs

Nicola Wren

Lucy

Wil Coban

Brother Blackleg

Jacqui Ainsley

Lady of the Lake

Georgina Campbell

Kay

Rob Knighton

Mordred

Michael Hadley

Mage King

David Beckham

Trigger

Alan Turkington

General 1

Michael McElhatton

Jack's Eye

Charlie Rawes

Axeman

James Warren

Mike

Ellie Graham

Maria

Kamil Lemieszewski

Merlin

Kalle Hennie

Viking

Peter Guinness

Baron 1

Mark Umbers

Baron 2

Adrian Bouchet

Baron 3

Florence Bell

Woman 1

Anna Brooks Beckman

Woman 2

Cordelia Bugeja

Woman 3

Rebecca Calder

Maid 1

Lee Nicholas Harris

Dan Clan Mafia (uncredited)

Gintare Beinoraviciute

Noble (uncredited)

Alice E. Mayer

Noble Girl (uncredited)

Claira Watson Parr

Noblewoman (uncredited)

Alphonso Austin

Slave Labourer (uncredited)

Rudy Barrow

Londinium Fighter (uncredited)

Daniel Stisen

SPAC / Londinum Fighter (uncredited)

Joel Bryant

Londinium Fighter (uncredited)

Dacio Caballero

Fighter (uncredited)

Lucy Chappell

Young Mother (uncredited)

Jamie B. Chambers

Knight (uncredited)

Pedro Caxade

Vortigern's Guard (uncredited)

Nick Cornwall

Clan Head 1 (uncredited)

Steve Barnett

Brothel Punter (uncredited)

Guy Ritchie

Inn Owner (uncredited)

Steen Young

Nemesis (uncredited)

Tom Coulston

Pendragon Soldier (uncredited)

Sarah-Jane De Crespigny

Low-Rent Villager (uncredited)

Karl Farrer

Nobleman (uncredited)