 | Ed Kemmer | ... | Cmdr. Buzz Corry (175 episodes, 1950-1955) |
 | Lyn Osborn | ... | Cadet Happy (170 episodes, 1950-1955) |
 | Nina Bara | ... | Tonga (138 episodes, 1951-1955) |
 | Ken Mayer | ... | Maj. Robbie Robertson (112 episodes, 1951-1955) |
 | Bela Kovacs | ... | Prince Baccarratti / ... (37 episodes, 1951-1955) |
 | Marvin Miller | ... | Mr. Proteus / ... (13 episodes, 1952-1954) |
 | Virginia Hewitt | ... | Carol Carlisle / ... (11 episodes, 1952-1955) |
 | Ben Welden | ... | Johnson / ... (9 episodes, 1952-1954) |
 | Tom McKee | ... | Ahyo / ... (8 episodes, 1953-1954) |
 | Joel Smith | ... | Android / ... (8 episodes, 1952-1955) |
 | Lawrence Dobkin | ... | Marco / ... (7 episodes, 1953-1955) |
 | Morgan Shaan | ... | Axel / ... (6 episodes, 1953-1954) |
 | Fred Howard | ... | Andrews / ... (6 episodes, 1951-1953) |
 | Richard Karlan | ... | Captain Dagger / ... (5 episodes, 1953-1954) |
 | Valerie Bales | ... | Yula / ... (4 episodes, 1955) |
 | Bill Baldwin | ... | Barti / ... (4 episodes, 1951-1954) |
 | Jack Reitzen | ... | Keller / ... (4 episodes, 1951-1953) |

| Lee Van Cleef | ... | Herrick / ... (4 episodes, 1952-1953) |
 | Charles Horvath | ... | Corporal / ... (4 episodes, 1952-1955) |
 | Robert Carson | ... | Governor Willis / ... (4 episodes, 1952-1953) |
 | Charles Victor | ... | Dr. Jerry Taylor / ... (4 episodes, 1953-1955) |
 | William Justine | ... | Benjamin / ... (4 episodes, 1953-1954) |
 | Robert Shayne | ... | Groata (3 episodes, 1954) |
 | Joel Marston | ... | Bill Redrow / ... (3 episodes, 1952-1954) |
 | Norbert Schiller | ... | Bit / ... (3 episodes, 1953-1955) |

| I. Stanford Jolley | ... | Dr. Lambert / ... (3 episodes, 1953-1954) |

| Oliver Blake | ... | Ezekial Martin (3 episodes, 1954) |
 | Dorothy Ford | ... | Queen Riva (3 episodes, 1954) |

| Henry Corden | ... | Brooks / ... (3 episodes, 1951-1953) |
 | Jack Brown | ... | Josiah / ... (3 episodes, 1954) |
 | Gail Bonney | ... | Goodwife Martin (3 episodes, 1954) |
 | Peter Mamakos | ... | Herrick / ... (3 episodes, 1951-1952) |
 | Ward Wood | ... | Farlon / ... (3 episodes, 1951-1952) |
 | John Alderson | ... | Bolen / ... (3 episodes, 1952-1953) |
 | Frederic Berest | ... | Bender / ... (3 episodes, 1952-1953) |
 | Stephen Chase | ... | Sloan / ... (3 episodes, 1952-1953) |
 | Leo V. Matranga | ... | Freddie / ... (3 episodes, 1952) |
 | William Boyett | ... | Guard / ... (3 episodes, 1953) |
 | Joe Cranston | ... | Guard / ... (3 episodes, 1953) |
 | Gabriel Curtiz | ... | Dr. Gruber / ... (3 episodes, 1953) |
 | Anne Dore | ... | Letha (3 episodes, 1953) |
 | Frances Farwell | ... | Calva (3 episodes, 1954) |
 | Norman Jolley | ... | Agent X (3 episodes, 1954) |
 | Hannes Lutz | ... | Doctor Kurt (3 episodes, 1954) |

| Gloria Pall | ... | Zamba (3 episodes, 1954) |
 | Kurt Katch | ... | Arachna (3 episodes, 1955) |
 | Paul Cavanagh | ... | Secretary General (2 episodes, 1955) |
 | Carleton Young | ... | Gen. Narda (2 episodes, 1954) |
 | Alvy Moore | ... | Ferris Macklin / ... (2 episodes, 1951-1952) |
 | Lisa Howard | ... | Lisa / ... (2 episodes, 1951) |
 | Keith Larsen | ... | Bradford / ... (2 episodes, 1952) |
 | Paul Guilfoyle | ... | Brunner / ... (2 episodes, 1952-1953) |
 | George Pembroke | ... | Carl Marsden / ... (2 episodes, 1952-1953) |
 | Jerry O'Sullivan | ... | Hefler / ... (2 episodes, 1952) |
 | Bert Holland | ... | The General (2 episodes, 1955) |
 | Hal Forrest | ... | Secretary General (2 episodes, 1953-1954) |
 | John Larch | ... | Korwin / ... (2 episodes, 1953-1954) |
 | Pierce Lyden | ... | Chaney / ... (2 episodes, 1951-1955) |
 | Jerry Sheldon | ... | Bit / ... (2 episodes, 1951-1955) |
 | William E. Green | ... | Pop Stanton / ... (2 episodes, 1951-1953) |
 | Richard Bartlett | ... | Harris / ... (2 episodes, 1951-1952) |
 | Maurice Hill | ... | Capt. Hayward / ... (2 episodes, 1951-1952) |

| William Schallert | ... | Craig / ... (2 episodes, 1951-1952) |
 | Jean Howell | ... | Nurse / ... (2 episodes, 1952-1954) |
 | Jan Arvan | ... | Kruse / ... (2 episodes, 1952-1953) |

| Phil Chambers | ... | Forman / ... (2 episodes, 1952-1953) |
 | Thomas Browne Henry | ... | Holliday / ... (2 episodes, 1952-1953) |
 | Bruce Payne | ... | Breckrenridge / ... (2 episodes, 1952-1953) |
 | Dan Seymour | ... | Kovel / ... (2 episodes, 1952-1953) |
 | Roland Varno | ... | Doc / ... (2 episodes, 1952-1953) |
 | George Douglas | ... | Bit / ... (2 episodes, 1953-1955) |
 | Marshall Bradford | ... | Perry / ... (2 episodes, 1953) |
 | Michael Colgan | ... | Fredericks / ... (2 episodes, 1953) |
 | Gene Roth | ... | Cole / ... (2 episodes, 1953) |
 | Lloyd Nelson | ... | Guard (2 episodes, 1954-1955) |
 | Ed Hinton | ... | Tyler (2 episodes, 1954) |
 | Jack Lynn | ... | Guard (2 episodes, 1954) |
 | Ed Taylor | ... | Bookstore Clerk / ... (2 episodes, 1954) |
|
 | Glen Denning | ... | Cmdr. Kit Corry (unknown episodes) |
 | Richard Devon | ... | Molak (unknown episodes, 1950) |