Jim Dale
Sir Mordred
Kenneth More
King Arthur
Ron Moody
Merlin
John Le Mesurier
Sir Gawain
Rodney Bewes
Clarence
Dennis Dugan
Tom Trimble
Pat Roach
Oaf
Sheila White
Alisande
Robert Beatty
Senator Milburn
Cyril Shaps
Dr. Zimmerman
K
Kevin Brennan
Winston
Ewen Solon
Watkins
Reg Lye
Prisoner
Bruce Boa
Air Force Officer (Uncredited)
Al Lampert
NASA Technician (Uncredited)
D
Derek Suthern
NASA VIP (Uncredited)