Clive Owen

Arthur

Ioan Gruffudd

Lancelot

Keira Knightley

Guinevere

Mads Mikkelsen

Tristan

Joel Edgerton

Gawain

Hugh Dancy

Galahad

Ray Winstone

Bors

Stephen Dillane

Merlin

Ray Stevenson

Dagonet

Til Schweiger

Cynric

Stellan Skarsgård

Cerdic

Sean Gilder

Jols

Ken Stott

Marius Honorius

Charlie Creed-Miles

Ganis

David Murray

Merlin's Lieutenant

Ned Dennehy

Mental Monk

Phelim Drew

Obnoxius Monk

Des Braiden

Third Monk

Bosco Hogan

Bishop Decoy

David Wilmot

Woad Killed by Lancelot

Lochlann Ó Mearáin

Roman Commander

Ivano Marescotti

Bishop Germanus

Clive Russell

Lancelot's Father

Graham McTavish

Roman Officer

Dessie Gallagher

Mercenary

Elliot Henderson-Boyle

Young Lancelot

Owen Teale

Pelagius (uncredited)

Dawn Bradfield

Vanora

Pat Kinevane

Horton

Paul Tall-Order Ritchie

Saxon (uncredited)

Lorenzo De Angelis

Alecto