David Graham

as Parker / Brains (voice)

Sylvia Anderson

as Lady Penelope (voice)

Shane Rimmer

as Scott Tracy (voice)

David Holliday

as Virgil Tracy (voice)

Francis Matthews

as Captain Scarlet (voice)

Ed Bishop

as Captain Blue (voice)

Donald Gray

as The Mysterons / Colonel White / Captain Black (voice)

Paul Maxwell

as Steve Zodiac / Captain Grey (voice)

Gerry Anderson

as Robert the Robot (voice, uncredited)