Robert Stack

Self

Stoat Muldoon (voice)

Reynolds Penland (voice) (uncredited)

Vic Flint

First Man

Superintendent (voice)

Bob (voice)

Agent Flemming (voice)

Host

Ultra Magnus (voice)

Chester Harrison

Captain Rex Kramer

Host - Narrator

Dr. Ellison

Bob Hayward

General Sibert

Cliff Henderson

Owen Pentecost

Nickey Van Alen

Don Webb