- Judd Holdren
- Commando Cody
- Aline Towne
- Joan Gilbert
- Richard Crane
- Dick Preston
- Gregory Gaye
- The Ruler
- William Schallert
- Ted Richards
- I. Stanford Jolley
- Hardy
- Craig Kelly
- Mr. Henderson
- Mauritz Hugo
- Baylen
- Dale Van Sickel
- Clancy
- Joanne Jordan
- Queen of Mercury
- Zon Murray
- Ross
- Gloria Pall
- The Moon Girl
- Denver Pyle
- Krug
- John Crawford
- Narkos
- William Henry
- (as Bill Henry) (credit only)
- Paul Livermore
- R-6 Pilot
- Keith Richards
- RG-12 Captain
- Lyle Talbot
- Baylor
- William Fawcett
- Old Chris
- Sydney Mason
- (credit only)
- Lee Roberts
- Alien Crewman
- Eddie Foster
- Mason
- Peter Ortiz
- Henchman
- Riley Hill
- Mercurian Soldier
- Rick Vallin
- (credit only)
- Kenneth MacDonald
- Dispersal Station Superintendent
- Peter Brocco
- Dr. Varney
- John Cason
- Henchman
- John Daheim
- Ed Williams
- Sandy Sanders
- Lead Henchman
- Stanley Waxman
- Lenato
- Roy Barcroft
- Point Barrow Radioman
- Lane Bradford
- Kirk
- Coleman Francis
- Security Guard
- Fred Graham
- Nordahl
- Charles Horvath
- Mercurian Guard
- Marshall Reed
- Bill
- Sam Sebby
- Guard #4
- Tom Steele
- Mercurian Guard
