Robert Taylor
Lancelot
Ava Gardner
Guinevere
Mel Ferrer
Arthur
Anne Crawford
Morgan Le Fay
Stanley Baker
Modred
Felix Aylmer
Merlin
Maureen Swanson
Elaine
Gabriel Woolf
Percival
Anthony Forwood
Gareth
Robert Urquhart
Gawaine
Niall MacGinnis
Green Knight
Ann Hanslip
Nan
Jill Clifford
Bronwyn
Stephen Vercoe
Agravaine
Alan Tilvern
Steward (uncredited)
Patricia Owens
Lady Vivien (uncredited)
Dana Wynter
Morgan Le Fay's servant (uncredited)