William Hartnell

The Doctor (1)

Anneke Wills

Polly

Michael Craze

Ben Jackson

Patrick Troughton

The Doctor (2) (uncredited)

Robert Beatty

General Cutler

David Dodimead

Barclay

Dudley Jones

Dyson

Alan White

Schultz

Earl Cameron

Williams

Callen Angelo

Terry Cutler

John Brandon

American Sergeant

Shane Shelton

Tito

Steve Plytas

Wigner

Christopher Matthews

Radar Technician

Ellen Cullen

Geneva Technician

Derek Martinus