Dr. Russell A. Marvin
Carol Marvin
Maj. Huglin
Brig. Gen. John Hanley
Vice Adm. Enright
Gen. Edmunds
Prof. Kanter
Alien (voice)
Alfred Cassidy
Frank the garage man
Motorcycle cop
Air Intelligence Command Officer
Military Officer at Experiment
Officer/Civilian at Military Conference
Major Kimberly
Military Officer at Experiment (uncredited)
Military Messenger (uncredited)
Military Officer (uncredited)
Dr. Alberts (uncredited)
Military Official (uncredited)
Alien (voice) (uncredited)
Military Official (uncredited)
Minor Role (uncredited)
Military Official (uncredited)
Sgt. Nash (uncredited)
Cutting - Generator Technician (uncredited)
Minor Role (uncredited)
Worker in Control Tower (uncredited)
Plane Passenger (uncredited)
Military Officer at Experiment (uncredited)
Radio Listener (archive footage) (uncredited)
Plane Passenger (uncredited)
Tank Commander (uncredited)
Maj. Kimberly (uncredited)
Man Crushed Beneath Wall (uncredited)
Civilian Observing Saucer Attack (uncredited)
Plane Passenger (uncredited)
Alfred Cassidy (uncredited)
Chinese Radio Listener (uncredited)
Narrator (voice) (uncredited)