William Hartnell as The Doctor (1)

Anneke Wills as Polly

Michael Craze as Ben Jackson

Patrick Troughton as The Doctor (2) (uncredited)

Robert Beatty as General Cutler

David Dodimead as Barclay

Dudley Jones as Dyson

Alan White as Schultz

Earl Cameron as Williams

Callen Angelo as Terry Cutler

John Brandon as American Sergeant

Shane Shelton as Tito

Steve Plytas as Wigner

Christopher Matthews as Radar Technician

Ellen Cullen as Geneva Technician

Christopher Dunham as R/T Technician

Glenn Beck as TV Announcer

Roy Skelton as Cybermen (voice)

Peter Hawkins as Cybermen (voice)

Harry Brooks as Cyberman

Reg Whitehead as Cyberman

Gregg Palmer as Cyberman