Arthur

Clive Owen

Lancelot

Ioan Gruffudd

Guinevere

Keira Knightley

Tristan

Mads Mikkelsen

Gawain

Joel Edgerton

Merlin

Stephen Dillane

Sir Galahad

Hugh Dancy

Cerdic

Stellan Skarsgard

Bors

Ray Winstone

Dagonet

Ray Stevenson

Cynric

Til Schweiger

Jols

Sean Gilder

Marius Honorius

Ken Stott

Ganis

Charlie Creed-Miles

Horton

Pat Kinevane

Bishop Germanius

Ivano Marescotti

Alecto

Lorenzo De Angelis

Fulcinia

Stefania Orsola Garello

Mental Monk

Ned Dennehy

Merlin's Lieutenant

David Murray

British Scout

Alan Devine

Obnoxious Monk

Phelim Drew

Third Monk

Des Braiden

Lucan

Johnny Brennan*

Bishop Decoy

Bosco Hogan

Woad Killed by Lancelot

David Wilmot

Roman Commander

Lochlainn O'Mearain

Lancelot's Father

Clive Russell

Cerdic Scout

Malachy McKenna

Roman Officer

Graham McTavish

Mercenary

Dessie Gallagher

Cerdic Officer

Brian McGuinness

Cerdic Officer

Patrick Leech

Young Lancelot

Elliot Henderson-Boyle

Pelagius (uncredited)

Owen Teale

Vanora

Dawn Bradfield

Mercenary

Paul McGlinchey

Arthur's Mother

Maria Gladkowska

Young Arthur

Shane Murray-Corcoran

Agustus

Daire McCormack

Scottish Village Girl

Lesley-Ann Shaw

Mangled Saxon

Joe McKinney

Woad Advisor

Gerry O'Brien

Cerdic Bodyguard

Brian Condon

Monk

Donncha Crowley

Saxon

Chick Allen

Lancelot's Mother

Stephanie Putson

Fulcinia

Valeria Cavalli

Lucan

John G. Brennan