Graham Chapman as King Arthur / Voice of God / Middle Head / Hiccoughing Guard

John Cleese as Second Swallow-Savvy Guard / The Black Knight / Peasant 3 / Sir Launcelot the Brave / Taunting French Guard / Tim the Enchanter

Eric Idle as Dead Collector / Peasant 1 / Sir Robin the Not-Quite-So-Brave-as-Sir Launcelot / First Swamp Castle Guard / Concorde / Roger the Shrubber / Brother Maynard

Terry Gilliam as Patsy / Green Knight / Old Man from Scene 24 (Bridgekeeper) / Sir Bors / Animator / Gorilla Hand

Terry Jones as Dennis's Mother / Sir Bedevere / Left Head / Prince Herbert / Voice of Cartoon Scribe

Michael Palin as First Swallow-Savvy Guard / Dennis / Peasant 2 / Right Head / Sir Galahad the Pure / Narrator / King of Swamp Castle / Brother Maynard's Brother / Leader of The Knights Who Say NI!

Connie Booth as The Witch

Carol Cleveland as Zoot / Dingo

Neil Innes as First Monk / Singing Minstrel / Page Crushed by the Rabbit / Peasant #4

Bee Duffell as Old Crone

John Young as Dead Body / Historian Frank

Rita Davies as Historian's Wife

Avril Stewart as Dr. Piglet

Sally Kinghorn as Dr. Winston

Mark Zycon as Prisoner

Elspeth Cameron as Girl in Castle Anthrax

Mitsuko Forstater as Girl in Castle Anthrax

Sandy Johnson as Knight of Ni / Villager at Witch Burning / Musician at Wedding / Monk / Knight in Battle

Sandy Rose as Girl in Castle Anthrax

Romilly Squire as Musician at Wedding / Villager at Witch Burning

Joni Flynn as Girl in Castle Anthrax

Alison Walker as Girl in Castle Anthrax

Loraine Ward as Girl in Castle Anthrax

Anna Lanski as Girl in Castle Anthrax

Sally Coombe as Girl in Castle Anthrax

Vivienne MacDonald as Girl in Castle Anthrax

Yvonne Dick as Girl in Castle Anthrax

Daphne Darling as Girl in Castle Anthrax

Fiona Gordon as Girl in Castle Anthrax

Judy Lamb as Girl in Castle Anthrax

Tracy Sneddon as Girl in Castle Anthrax

Joyce Pollner as Girl in Castle Anthrax

Mary Allen as Girl in Castle Anthrax

Gloria Graham as Girl in Castle Anthrax

Sylvia Taylor as Girl in Castle Anthrax

Iain Banks as Knight in Battle (uncredited)

Julian Doyle as Police Sergeant (uncredited)

Margarita Doyle as Peasant (uncredited)

Charles Knode as Camp Guard / Robin's Minstrel (uncredited)

Zack Matalon as Guard who Falls into Barrels (uncredited)

Scott Mike as Bash (Mudfighter (uncredited)

William Palin as Sir Not-Appearing-in-this-Film (uncredited)

Tom Raeburn as Guard Eating Apple (uncredited)

Brian Ross as Biff (Mudfighter) (uncredited)

Roy Forge Smith as Inspector End of Film (uncredited)

Maggie Weston as Page-turner (uncredited)

John Thornton as Dancing Knight (uncredited)