- Ed Kemmer
- Â Cmdr. Buzz Corry 182 episodes, 1950-1955
- Lyn Osborn
- Â Cadet Happy 176 episodes, 1950-1955
- Nina Bara
- Â Tonga 145 episodes, 1950-1955
- Ken Mayer
- Â Maj. Robbie Robertson 118 episodes, 1950-1955
- Bela Kovacs
- Â Prince Baccarratti / ... 38 episodes, 1951-1955
- Virginia Hewitt
- Â Carol Carlisle / ... 19 episodes, 1950-1955
- Marvin Miller
- Â Mr. Proteus / ... 14 episodes, 1952-1954
- Ben Welden
- Â Johnson / ... 9 episodes, 1952-1954
- Tom McKee
- Â Ahyo / ... 8 episodes, 1953-1954
- Joel Smith
- Â Android / ... 7 episodes, 1952-1955
- Paul Cavanagh
- Â Colonel Henderson / ... 7 episodes, 1950-1955
- Lawrence Dobkin
- Â Marco / ... 7 episodes, 1953-1955
- Morgan Shaan
- Â Axel / ... 6 episodes, 1953-1954
- Howard Wright
- Â Andrews / ... 6 episodes, 1951-1953
- Richard Karlan
- Â Captain Dagger / ... 5 episodes, 1953-1954
- Valerie Bales
- Â Yula / ... 4 episodes, 1955
- Bill Baldwin
- Â Barti / ... 4 episodes, 1951-1954
- Jack Reitzen
- Â Keller / ... 4 episodes, 1951-1953
- Lee Van Cleef
- Â Herrick / ... 4 episodes, 1952-1953
- Charles Horvath
- Â Corporal / ... 4 episodes, 1952-1955
- Peter Mamakos
- Â Herrick / ... 4 episodes, 1950-1952
- Robert Carson
- Â Governor Willis / ... 4 episodes, 1952-1953
- Charles Victor
- Â Dr. Jerry Taylor / ... 4 episodes, 1953-1955
- Gabriel Curtiz
- Â Dr. Malengro / ... 4 episodes, 1953-1954
- William Justine
- Â Benjamin / ... 4 episodes, 1953-1954
- Norman Jolley
- Â Agent X 4 episodes, 1954
- Robert Shayne
- Â Groata 3 episodes, 1954
- Joel Marston
- Â Bill Redrow / ... 3 episodes, 1952-1954
- Norbert Schiller
- Â Bit / ... 3 episodes, 1953-1955
- I. Stanford Jolley
- Â Dr. Lambert / ... 3 episodes, 1953-1954
- Dorothy Ford
- Â Queen Riva 3 episodes, 1954
- Oliver Blake
- Â Ezekial Martin 3 episodes, 1954
- Henry Corden
- Â Brooks / ... 3 episodes, 1951-1953
- Hal Forrest
- Â Secretary General / ... 3 episodes, 1953-1954
- Jack Brown
- Â Josiah / ... 3 episodes, 1954
- Gail Bonney
- Â Goodwife Martin 3 episodes, 1954
- Jack Narz
- Â Announcer / ... 1 episode, 1951-1952
- Ward Wood
- Â Farlon / ... 3 episodes, 1951-1952
- John Alderson
- Â Bolen / ... 3 episodes, 1952-1953
- Stephen Chase
- Â Sloan / ... 3 episodes, 1952-1953
- Frederic Berest
- Â Bender / ... 3 episodes, 1952-1953
- Leo V. Matranga
- Â Freddie / ... 3 episodes, 1952
- Edward Taylor
- Â Bookstore Clerk / ... 1 episode, 1953-1954
- William Boyett
- Â Guard / ... 3 episodes, 1953
- Joe Cranston
- Â Guard / ... 3 episodes, 1953
- Anne Dore
- Â Letha 3 episodes, 1953
- Gloria Pall
- Â Zamba 2 episodes, 1954
- Frances Farwell
- Â Calva 2 episodes, 1954
- Hannes Lutz
- Â Doctor Kurt 3 episodes, 1954
- Kurt Katch
- Â Arachna 3 episodes, 1955
- Carleton Young
- Â Gen. Narda 2 episodes, 1954
- Alvy Moore
- Â Ferris Macklin / ... 2 episodes, 1951-1952
- Lisa Howard
- Â Lisa / ... 2 episodes, 1951
- Keith Larsen
- Â Bradford / ... 2 episodes, 1952
- Paul Guilfoyle
- Â Brunner / ... 2 episodes, 1952-1953
- George Pembroke
- Â Carl Marsden / ... 2 episodes, 1952-1953
- Jerry O'Sullivan
- Â Hefler / ... 2 episodes, 1952
- Rudolph Anders
- Â Doctor Van Meter / ... 2 episodes, 1954
- Harold Gordon
- Â Doctor Maddox / ... 2 episodes, 1954
- Bert Holland
- Â The General 2 episodes, 1955
- John Larch
- Â Korwin / ... 2 episodes, 1953-1954
- Don Gordon
- Â Captain Pasko / ... 2 episodes, 1950-1951
- Jesse Wayne
- Â Bit 2 episodes, 1950
- Pierce Lyden
- Â Chaney / ... 2 episodes, 1951-1955
- Jerry Sheldon
- Â Bit / ... 2 episodes, 1951-1955
- William E. Green
- Â Pop Stanton / ... 2 episodes, 1951-1953
- William Schallert
- Â Craig / ... 2 episodes, 1951-1952
- Maurice Hill
- Â Capt. Hayward / ... 2 episodes, 1951-1952
- Richard Bartlett
- Â Harris / ... 2 episodes, 1951-1952
- Jean Howell
- Â Nurse / ... 2 episodes, 1952-1954
- Dan Seymour
- Â Kovel / ... 2 episodes, 1952-1953
- Thomas Browne Henry
- Â Holliday / ... 2 episodes, 1952-1953
- Jan Arvan
- Â Kruse / ... 2 episodes, 1952-1953
- Phil Chambers
- Â Forman / ... 2 episodes, 1952-1953
- Roland Varno
- Â Doc / ... 2 episodes, 1952-1953
- Bruce Payne
- Â Breckrenridge / ... 2 episodes, 1952-1953
- George Douglas
- Â Bit / ... 2 episodes, 1953-1955
- Gene Roth
- Â Cole / ... 2 episodes, 1953
- Marshall Bradford
- Â Perry / ... 2 episodes, 1953
- Michael Colgan
- Â Fredericks / ... 2 episodes, 1953
- Lloyd Nelson
- Â Guard 1 episode, 1954-1955
- Ed Hinton
- Â Tyler 2 episodes, 1954
- Jack Lynn
- Â Guard 2 episodes, 1954
- Arthur Marshall
- Â Malin 1 episode, 1953
- Richard Norris
- Â John 1 episode, 1951
- Jane Davids
- Â Jo Vance 1 episode, 1951
- Henry Rowland
- Â Max 1 episode, 1952
- Edith Evanson
- Â Aunt Sybil Todd 1 episode, 1953
- Frank Richards
- Â King 1 episode, 1954
- Don Jones
- Â Johnson 1 episode, 1952
- Earl Lee
- Â Lowell 1 episode, 1953
- John Halloran
- Â Salbo 1 episode, 1953
- Wayne Taylor
- Â Truck Todd 1 episode, 1953
- Janet Dascher
- Â The Girl 1 episode, 1954
- Richard Devon
- Â Molock 1 episode, 1954
- Vicki Bakken
- Â Marta 1 episode, 1950
- Dabbs Greer
- Â Paul Marin 1 episode, 1951
- George Chandler
- Â Fred Masterson 1 episode, 1951
- Sam Edwards
- Â Eric Werner 1 episode, 1951
- Emil Sitka
- Â Pete 1 episode, 1951
- Sue England
- Â Terry 1 episode, 1951
- Sara Berner
- Â Sara 1 episode, 1951
- James Nusser
- Â Ben 1 episode, 1951
- Stephen Coit
- Â Lt. Conway 1 episode, 1951
- David Bair
- Â Governor's Son 1 episode, 1951
- Hans Schumm
- Â Brewer 1 episode, 1951
- Glenn Dixon
- Â Space Patrol Major Gruel 1 episode, 1951
- Crane Whitley
- Â Kessler 1 episode, 1951
- Anne Diamond
- Â Alicia 1 episode, 1951
- Perry Evans
- Â Brand 1 episode, 1951
- Peter Foster
- Â Zurach 1 episode, 1951
- Wayne Winton
- Â Gerald Mazzman 1 episode, 1951
- George Demetrios
- Â Dr. Smatka 1 episode, 1951
- Jack Wilson
- Â Fairhorn 1 episode, 1951
- James Clay
- Â Ghent 1 episode, 1951
- John Mel
- Â Thutmon 1 episode, 1951
- Richard Bergren
- Â Lt. Gethard 1 episode, 1951
- Glenn Strange
- Â Captain Jonas 1 episode, 1952
- Lyle Talbot
- Â Cadwalader 1 episode, 1952
- Stanley Andrews
- Â Barrow 1 episode, 1952
- James Dobson
- Â Cadet Cramer 1 episode, 1952
- Will J. White
- Â Tharl 1 episode, 1952
- Robert Knapp
- Â Lt. Bruce 1 episode, 1952
- Ludwig Donath
- Â Professor Bradshaw 1 episode, 1952
- Tom Daly
- Â Klinger 1 episode, 1952
- Clark Howat
- Â Manson 1 episode, 1952
- Gloria Saunders
- Â Lois 1 episode, 1952
- Tracey Roberts
- Â Therma 1 episode, 1952
- Jimmy Boyd
- Â Jimmy 1 episode, 1952
- Mona Knox
- Â Lanya 1 episode, 1952
- Stanley Farrar
- Â Lennan 1 episode, 1952
- Lou Nova
- Â Igor 1 episode, 1952
- Harold Dyrenforth
- Â Sandor 1 episode, 1952
- Tony Michaels
- Â Mechanic 1 episode, 1952
- Robert Beecher
- Â Gar 1 episode, 1952
- James Logan
- Â Todd 1 episode, 1952
- Evelyn Eaton
- Â Miss Wagner 1 episode, 1952
- Robert Dane
- Â Hoag 1 episode, 1952
- Inge Borg
- Â Erika 1 episode, 1952
- Howard Price
- Â Graham 1 episode, 1952
- James Bronte
- Â Malcolm 1 episode, 1952
- Liba Petrova
- Â Jana 1 episode, 1952
- Joyce Craig
- Â Lola 1 episode, 1952
- Gordon Grange
- Â Andy 1 episode, 1952
- John Roth
- Â Bruta 1 episode, 1952
- Albert Taylor
- Â Nazi Lieutenant 1 episode, 1952
- Elaine Williams
- Â Maleeva 1 episode, 1952
- Douglas Grange
- Â Benson 1 episode, 1952
- Paul Richards
- Â Guard 1 episode, 1953
- Billy Curtis
- Â Gino 1 episode, 1953
- Sally Fraser
- Â Linda 1 episode, 1953
- Elizabeth Harrower
- Â Woman 1 episode, 1953
- Eddie Ryder
- Â Ronald 1 episode, 1953
- Lee Millar
- Â Guard 1 episode, 1953
- Dran Hamilton
- Â Miss Gordon 1 episode, 1953
- Leonard Bremen
- Â Stone 1 episode, 1953
- Gilman Rankin
- Â Craig 1 episode, 1953
- Harry Monty
- Â Mario 1 episode, 1953
- Isa Ashdown
- Â Millie 1 episode, 1953
- Lee Morgan
- Â Kazer 1 episode, 1953
- Kem Dibbs
- Â Hendrix 1 episode, 1953
- Jeffrey Silver
- Â Rudy 1 episode, 1953
- John Damler
- Â Number 2 1 episode, 1953
- Edward Clark
- Â Harkins 1 episode, 1953
- Paul Keast
- Â White 1 episode, 1953
- Karl 'Killer' Davis
- Â Durk 1 episode, 1953
- Jean Gale
- Â Judy 1 episode, 1953
- Jean Howard
- Â Irene 1 episode, 1953
- Ramsay Hill
- Â Governor Marin 1 episode, 1953
- Donald Lawton
- Â Barrow 1 episode, 1953
- Hal Gerard
- Â Brenner 1 episode, 1953
- Marvin Press
- Â Harper 1 episode, 1953
- Mickey Little
- Â Danny 1 episode, 1953
- Robert Shafto
- Â Professor Walton 1 episode, 1953
- Michael Hale
- Â Doctor Brockway 1 episode, 1953
- Toni Seitz
- Â Sara 1 episode, 1953
- Ruth Gur
- Â Riva 1 episode, 1953
- Paul Klatt Jr.
- Â Rollo 1 episode, 1953
- Rand Brooks
- Â Guard 1 episode, 1954
- Kerwin Mathews
- Â Major Caldwell 1 episode, 1954
- Peter Hansen
- Â Doctor Paul Yates 1 episode, 1954
- Jean Inness
- Â Bess Osborn 1 episode, 1954
- Robert Nash
- Â Doctor Lorenz 1 episode, 1954
- George Baxter
- Â Gart Stanger 1 episode, 1954
- Glen Denning
- Â Commander Kit Corry 1 episode, 1954
- Jack McHugh
- Â Major Sova 1 episode, 1954
- Charles Calvert
- Â Bill Osborn 1 episode, 1954
- Don Hicks
- Â Guard 1 episode, 1954
- Bill Bryar
- Â Guard 1 episode, 1954
- Howard Culver
- Â Bit 1 episode, 1955
- Robert Boon
- Â Lieutenant Rayzo 1 episode, 1955
- Phil Sutton
- Â Guard #2 1 episode, 1955
- Dick Tufeld
- Â Announcer (uncredited) 1 episode, 1953
- LeRoy Lennart
- Â Police Officer Carson (uncredited) 1 episode, 1954
- Richard Weil
- Â Harris (uncredited) 1 episode, 1954
