- Ed Bishop
- Â Commander Ed Straker 26 episodes, 1970-1971
- Dolores Mantez
- Â Lieutenant Nina Barry 23 episodes, 1970-1971
- Michael Billington
- Â Colonel Paul Foster / ... 21 episodes, 1970-1971
- Ayshea Brough
- Â Lieutenant Ayshea Johnson 18 episodes, 1970-1971
- George Sewell
- Â Colonel Alec Freeman 17 episodes, 1970-1971
- Keith Alexander
- Â Lieutenant Keith Ford 15 episodes, 1970-1971
- Antonia Ellis
- Â Lieutenant Joan Harrington 13 episodes, 1970-1971
- Gary Myers
- Â Captain Lew Waterman 10 episodes, 1970-1971
- Gabrielle Drake
- Â Lieutenant Gay Ellis 10 episodes, 1970-1971
- Vladek Sheybal
- Â Dr. Doug Jackson 10 episodes, 1970-1971
- Jon Kelley
- Â Skydiver Engineer / ... 10 episodes, 1970-1971
- Norma Ronald
- Â Miss Ealand 9 episodes, 1970-1971
- Wanda Ventham
- Â Colonel Virginia Lake 9 episodes, 1970-1971
- Grant Taylor
- Â General James Henderson 9 episodes, 1970-1971
- Jeremy Wilkin
- Â Skydiver Navigator / ... 8 episodes, 1970-1971
- Georgina Moon
- Â Lieutenant Sylvia Howell 7 episodes, 1970-1971
- Harry Baird
- Â Lieutenant Mark Bradley 6 episodes, 1970
- Peter Gordeno
- Â Capt. Carlin 6 episodes, 1970-1971
- Andrea Allan
- Â Moonbase Operative Carol Miller / ... 3 episodes, 1970-1971
- Anouska Hempel
- Â SHADO Radio Operator Tamara Paulson / ... 4 episodes, 1971
- Steven Berkoff
- Â Captain Steve Minto 4 episodes, 1970-1971
- Maxwell Shaw
- Â Dr. Shroeder 4 episodes, 1970-1971
- Basil Moss
- Â Dr. Frazer / ... 4 episodes, 1970-1971
- Gito Santana
- Â Alien 2 episodes, 1970-1971
- Alan Tucker
- Â Lunar Module Pilot / ... 3 episodes, 1970-1971
- Mark Hawkins
- Â Astronaut / ... 3 episodes, 1970-1971
- Shane Rimmer
- Â Lt. Bill Johnson / ... 2 episodes, 1970
- John Lyons
- Â SHADO Checkpoint Guard / ... 2 episodes, 1970-1971
- Peter Burton
- Â Dr. Murray / ... 2 episodes, 1970
- Penny Spencer
- Â SHADO Operative / ... 1 episode, 1970-1971
- Al Mancini
- Â Lt. Andy Conroy 2 episodes, 1970-1971
- Burnell Tucker
- Â Albatross Pilot Turner / ... 2 episodes, 1970-1971
- Philip Madoc
- Â Ship's Capt. / ... 3 episodes, 1970-1971
- Craig Hunter
- Â G.S.P. 4 Pilot Hudson / ... 2 episodes, 1971
- Peter Blythe
- Â 2nd Officer / ... 2 episodes, 1970
- Suzanne Neve
- Â Mary Rutland / ... 3 episodes, 1970-1971
- Gordon Sterne
- Â German Delegate / ... 2 episodes, 1970-1971
- Michael Mundell
- Â Ken Matthews 2 episodes, 1970
- Anthony Chinn
- Â Alien / ... 2 episodes, 1970
- Lois Maxwell
- Â Miss Holland 2 episodes, 1970-1971
- Louise Pajo
- Â Miss Scott / ... 2 episodes, 1970
- David Warbeck
- Â Skydiver Captain 2 episodes, 1970-1971
- David Weston
- Â Mitchell / ... 2 episodes, 1970-1971
- Barry Stokes
- Â Skydiver Engineer 2 episodes, 1970-1971
- Nigel Gregory
- Â Ben Culley / ... 2 episodes, 1970-1971
- Stanley McGeagh
- Â SHADO Guard / ... 2 episodes, 1970-1971
- Tom Oliver
- Â 1st Technician / ... 2 episodes, 1970-1971
- Stephanie Beacham
- Â Sarah Bosanquet 2 episodes, 1970
- Dennis Plenty
- Â Lt. David Worth / ... 1 episode, 1970
- Norton Clarke
- Â 1st Assistant Director / ... 1 episode, 1971
- Adrienne Corri
- Â Liz Newton 1 episode, 1970
- Robert Swann
- Â Grant 1 episode, 1970
- John Stratton
- Â John Croxley 1 episode, 1970
- Barnaby Shaw
- Â John Rutland 2 episodes, 1970-1971
- Gerald Norman
- Â Pilot - Space Ship 1 episode, 1970
- Frank E. Stranges
- Â Doctor Stranges 1 episode, 1971
- Keith Grenville
- Â Dawson 1 episode, 1971
- Douglas Nottage
- Â SHADO Maintenance Engineer 1 episode, 1971
- Alexis Kanner
- Â Lt. Jim Regan 1 episode, 1970
- Deborah Stanford
- Â Stella Croxley 1 episode, 1970
- George Cole
- Â Paul Roper 1 episode, 1971
- Conrad Phillips
- Â Skipper 1 episode, 1971
- David Sumner
- Â Captain Frank Craig 1 episode, 1970
- Donald Tandy
- Â Gateman 1 episode, 1970
- Jimmy Winston
- Â Rating 1 episode, 1970
- Derren Nesbitt
- Â Colonel Craig Collins 1 episode, 1971
- Fredric Abbott
- Â 1st Seaman 1 episode, 1971
- Douglas Wilmer
-  Dr. Brünner / ... 1 episode, 1970
- Deborah Grant
- Â Linda Simmonds 1 episode, 1970
- Basil Dignam
- Â Cabinet Minister 2 episodes, 1970-1971
- Michael Ferrand
- Â Radar Technician 1 episode, 1970
- Tracy Reed
- Â Jane Carson 1 episode, 1971
- Tessa Wyatt
- Â Catherine Frazer 1 episode, 1971
- Sonia Fox
- Â Carol Roper 1 episode, 1971
- Richard Caldicot
- Â Film Producer 1 episode, 1971
- David Collings
- Â Daniel Clark 1 episode, 1970
- Quinn O'Hara
- Â Sylvia Graham 1 episode, 1970
- Robert Lloyd
- Â Radar Officer 1 episode, 1970
- Julian Grant
- Â Lt. David Grey 1 episode, 1970
- Christian Roberts
- Â Tim Redman 1 episode, 1971
- Clinton Greyn
- Â Tanner 1 episode, 1971
- Paul Maxwell
- Â Lt. Jim Lewis 1 episode, 1970
- Mike Pratt
- Â Clem Mason 1 episode, 1970
- Drewe Henley
- Â Maddox 1 episode, 1970
- James Cosmo
- Â Lt. Anderson 1 episode, 1971
- Jane Merrow
- Â Jo Fraser 1 episode, 1971
- Geoffrey Hinsliff
- Â Hotel Clerk 1 episode, 1970
- Gavin Campbell
- Â Police Motorcyclist 1 episode, 1970
- Ron Pember
- Â Casting Agent 1 episode, 1971
- David Griffith
- Â Underwater Cameraman 1 episode, 1971
- John Garrie
- Â Van Driver 1 episode, 1971
- Ralph Ball
- Â Film Director 1 episode, 1971
- Windsor Davies
- Â Morgan 1 episode, 1970
- Michael Forrest
- Â Security Officer 1 episode, 1970
- James Beckett
- Â Dr. Young 1 episode, 1970
- Noel Davis
- Â Artist's Agent 1 episode, 1970
- David Courtland
- Â Crewman - Lunar Module 1 episode, 1970
- Michael Jayston
- Â Russell Stone 1 episode, 1971
- Keith Bell
- Â Film Director 1 episode, 1971
- Christopher Robbie
- Â Bomb Disposal Expert 1 episode, 1971
- Jean Wladon
- Â Actor 1 episode, 1971
- Royston Rowe
- Â Stunt Man 1 episode, 1971
- Suzan Farmer
- Â Tina Duval 1 episode, 1970
- Patrick Mower
- Â Cass Fowler 1 episode, 1970
- Geraldine Moffat
- Â Jean Regan 1 episode, 1970
- Pippa Steel
- Â Diane 1 episode, 1970
- David Cargill
- Â Car Driver 1 episode, 1970
- John Golightly
- Â Holden 1 episode, 1970
- Frank Tregear
- Â Porter 1 episode, 1970
- Susan Jameson
- Â Anne Stone 1 episode, 1971
- Gary Raymond
- Â Colonel John Grey 1 episode, 1971
- Larry Taylor
- Â 1st Mexican Bandit 1 episode, 1971
- Kirsten Lindholm
- Â Actress 1 episode, 1971
- Gerald Cross
- Â Insurance Man 1 episode, 1971
- Jack Hedley
- Â Webb 1 episode, 1970
- David Healy
- Â Joe Franklin 1 episode, 1970
- Eleanor Summerfield
- Â Muriel Thompson 1 episode, 1970
- Neil Hallett
- Â Kelly 1 episode, 1970
- Nigel Lambert
- Â Moonbase Operative 1 episode, 1970
- Ray Armstrong
- Â Rescuer 1 episode, 1970
- Matt Zimmerman
- Â Co-Pilot 1 episode, 1970
- Alan Haywood
- Â SHADO Diver Ross 1 episode, 1970
- Patrick Allen
- Â Turner 1 episode, 1971
- Ricardo Montez
- Â 2nd Mexican Bandit 1 episode, 1971
- Colin Gordon
- Â Albert Thompson 1 episode, 1970
- Peter Davies
- Â Fairfield Tracker Station Guard 1 episode, 1970
- Steve Cory
- Â Moonbase Guard 1 episode, 1970
- Michael Stevens
- Â Chauffeur 1 episode, 1971
- Bill Morgan
- Â 3rd Mexican Bandit 1 episode, 1971
- Peter Halliday
- Â Dr. Segal 2 episodes, 1970-1971
- Neil McCallum
- Â Carl Mason 1 episode, 1970
- Jack May
- Â English Delegate 1 episode, 1970
- Hugo Panczak
- Â SHADO Mobile Navigator 1 episode, 1970
- Sue Gerrard
- Â Nurse 1 episode, 1970
- Derek Steen
- Â Fairfield Tracker Station Guard 1 episode, 1970
- Richard Vernon
- Â Pa Stone 1 episode, 1971
- Roland Culver
- Â Sir Esmond 1 episode, 1971
- Philip Latham
- Â Blake 1 episode, 1971
- Tom Adams
- Â Captain Lauritzen 1 episode, 1970
- Edwin Richfield
- Â Admiral Sheringham 1 episode, 1970
- Godfrey James
- Â Game Warden 1 episode, 1970
- Jeffrey Segal
- Â Monsieur Duval 1 episode, 1970
- Paul Greenhalgh
- Â Assistant Director 1 episode, 1970
- Frank Mann
- Â Rocket Launch Controller 1 episode, 1970
- Alexander Davion
- Â The Executive 1 episode, 1970
- Robin Bailey
- Â Kofax 1 episode, 1970
- Charles 'Bud' Tingwell
- Â Captain Beaver James 1 episode, 1971
- John Breslin
- Â Reed 1 episode, 1971
- Malcolm Reynolds
- Â 2nd Technician 1 episode, 1971
- Robert Grange
- Â Moonbase Doctor 1 episode, 1971
- Christopher Timothy
- Â Skydiver 3 Navigator 1 episode, 1970
- Allan Cuthbertson
- Â Jack Newton 1 episode, 1970
- Alan Tilvern
- Â U.S. Delegate 1 episode, 1970
- Georgina Cookson
- Â Jane Grant 1 episode, 1970
- Michael Kilgarriff
- Â Steiner 1 episode, 1970
- Paula Li Shiu
- Â Tsi 1 episode, 1970
- John J. Carney
- Â Studio Security Man 1 episode, 1971
- Nancy Nevinson
- Â Housekeeper 1 episode, 1971
- Mary Merrall
- Â Mrs. O'Connor 1 episode, 1970
- Robin Hawdon
- Â Skydiver 3 Captain 1 episode, 1970
- Donald Pelmear
- Â Estate Agent 1 episode, 1970
- Hein Viljoen
- Â SHADO Mobile 1 Personnel 1 episode, 1970
- Michael Glover
- Â Guard 1 episode, 1970
- James Marcus
- Â SHADO Operative 1 episode, 1971
- Fred Real
- Â Porter 1 episode, 1971
- John Cobner
- Â Moonmobile Captain 1 episode, 1971
- Jean Marsh
- Â Janna 1 episode, 1970
- Russell Napier
- Â Dr. Green 1 episode, 1970
- Paul Gillard
- Â Kurt Mahler 1 episode, 1970
- David Savile
- Â Hospital Doctor 1 episode, 1971
- Richard Poore
- Â Moonmobile Lt. 1 episode, 1971
- Tutte Lemkow
- Â Singleton 1 episode, 1970
- Hugh Armstrong
- Â SHADO Mobile 3 Officer 1 episode, 1970
- Luke Hanson
- Â Security Man 1 episode, 1970
- Richard Aylen
- Â Alien 1 episode, 1970
- Joseph Morris
- Â Medic 1 episode, 1970
- Rona Newton-John
- Â Nurse 1 episode, 1971
- Patrick Jordan
- Â Russian Base Cmdr. 1 episode, 1971
- Arthur Cox
- Â Louis 1 episode, 1970
- Gary Files
- Â Phil Wade 1 episode, 1970
- Peter Dolphin
- Â Skydiver 3 Engineer 1 episode, 1970
- Stuart Damon
- Â Howard Byrne 1 episode, 1971
- Janos Kurucz
- Â Russian Astronaut 1 episode, 1971
- Michael Nightingale
- Â Mary's Father 1 episode, 1970
- Mark York
- Â Skydiver 3 Engineer 1 episode, 1970
- Matthew Roberton
- Â Dr. Harris 1 episode, 1970
- Stephan Chase
- Â Film Director 1 episode, 1971
- Paul Tamarin
- Â Russian Astronaut 1 episode, 1971
- Oscar James
- Â Plain Clothes Officer 1 episode, 1970
- Aidan Murphy
- Â Room 22 Guard 1 episode, 1970
- Annette Kerr
- Â Nurse 1 episode, 1970
- Penny Jackson
- Â Nurse 1 episode, 1970
- Paul Greaves
- Â 2nd Assistant Director 1 episode, 1971
- Mel Oxley
- Â Space Intruder Detector SID (uncredited) 25 episodes, 1970-1971
- John Clifford
- Â SHADO Operative (uncredited) 5 episodes, 1970-1971
- Shakira Caine
- Â SHADO Operative / ... (uncredited) 4 episodes, 1970-1971
- Alan Harris
- Â Interceptor Pilot / ... (uncredited) 3 episodes, 1970-1971
- Diana Reeves
- Â SHADO Operative (uncredited) 3 episodes, 1970
- Bill Hemmings
- Â Seaman / ... (uncredited) 2 episodes, 1970-1971
- Lew Hooper
- Â Carpenter / ... (uncredited) 2 episodes, 1970-1971
- Bill Burns
- Â Skydiver Operative (uncredited) 2 episodes, 1970
- Bill Strange
- Â Moonbase Security / ... (uncredited) 2 episodes, 1971
- Stuart Wilson
- Â Man at party (uncredited) 1 episode, 1970
- Bob Sherman
- Â Launch Control 1st Operative (uncredited) 1 episode, 1970
- Robert Rietty
- Â Keith Ford (uncredited) 1 episode, 1970
- John Levene
- Â Interceptor Pilot (uncredited) 1 episode, 1970
- Edwina Carroll
- Â Leila Carlin (uncredited) 1 episode, 1970
- Terence Conoley
- Â Studio Crew (uncredited) 1 episode, 1970
- Reg Thomason
- Â Bar Patron (uncredited) 1 episode, 1970
- Aileen Lewis
- Â Wedding Reception Guest (uncredited) 1 episode, 1970
- Lewis Alexander
- Â Wedding Reception Guest (uncredited) 1 episode, 1970
- Pat Ryan
- Â Judge (uncredited) 1 episode, 1970
- Maureen Nelson
- Â Film Crew (uncredited) 1 episode, 1970
- Ernest Fennemore
- Â Ambulanceman (uncredited) 1 episode, 1970
- Gerald Paris
- Â Delegate (uncredited) 1 episode, 1970
- Jack Silk
- Â Motorcyclist (uncredited) 1 episode, 1970-1971
- Jack Arrow
- Â Bar Patron (uncredited) 1 episode, 1970
- Reg Turner
- Â Technician (uncredited) 1 episode, 1970
- Harold Coyne
- Â Studio Crew (uncredited) 1 episode, 1970
- Peter Roy
- Â Hospital Porter (uncredited) 1 episode, 1970
- Clive Endersby
- Â Launch Control Harry (uncredited) 1 episode, 1970
- Derek Chafer
- Â SHADO Operative (uncredited) 1 episode, 1970
- Ned Lynch
- Â Astro Space Commision Member (uncredited) 1 episode, 1970
- Harry Van Engel
- Â Pilot (uncredited) 1 episode, 1970
- Rosemary Donnelly
- Â SHADO Operative (uncredited) 1 episode, 1970
- Bill Westley Sr.
- Â Passerby (uncredited) 1 episode, 1970
- Rodney Cardiff
- Â Man at Party (uncredited) 1 episode, 1970
- Harry Tierney
- Â Launch Control Operative (uncredited) 1 episode, 1970
- Jack Ross
- Â Barman (uncredited) 1 episode, 1970
- Louisa Rabaiotti
- Â SHADO Operative (uncredited) 1 episode, 1970
- Sandy Shelton
- Â Bar Patron (uncredited) 1 episode, 1970
- Mickey Varey
- Â Road Builder (uncredited) 1 episode, 1970
- Bob Howay
- Â Launch Control 2nd Operative (uncredited) 1 episode, 1970
- Malcolm Johns
- Â Security Man (uncredited) 1 episode, 1970
- Stanley Bray
- Â Alien (uncredited) 1 episode, 1970
- Gideon Kolb
- Â Wedding Reception Guest (uncredited) 1 episode, 1970
- Stenson Falke
- Â Astro Space Commision Member (uncredited) 1 episode, 1970
- Ron Whitwell
- Â Astro Space Commission Member (uncredited) 1 episode, 1970
- Clive Rogers
- Â Wedding Reception Guest (uncredited) 1 episode, 1970
- John Triplett
- Â Studio Crew (uncredited) 1 episode, 1970
- David Daker
- Â SHADO Guard (uncredited) 1 episode, 1971
- Maxwell Craig
- Â Assassin (uncredited) 1 episode, 1971
- Bob Simmons
- Â SHADO Operative (uncredited) 1 episode, 1971
- George Leech
- Â Alien (uncredited) 1 episode, 1971
- Roy Beck
- Â SHADO Security Guard (uncredited) 1 episode, 1971
- Colin Skeaping
- Â SHADO Operative (uncredited) 1 episode, 1971
- Stan Simmons
- Â Hovercraft Pilot (uncredited) 1 episode, 1971
- John Corrie
- Â Carpenter (uncredited) 1 episode, 1971
- Vic Chapman
- Â Carpenter (uncredited) 1 episode, 1971
- Fred Machon
- Â Assistant Director (uncredited) 1 episode, 1971
- Janice Hoy
- Â SHADO Operative (uncredited) 1 episode, 1971
- John Ketteringham
- Â Studio Crew (uncredited) 1 episode, 1971
- Larry Sheppard
- Â Man on Pleasure Boat (uncredited) 1 episode, 1971
- Donald Campbell
- Â Boatman (uncredited) 1 episode, 1971
- Christine Smith
- Â Secretary Frozen in Time (uncredited) 1 episode, 1971
- Maureen Tann
- Â Moonbase Operative (uncredited) 1 episode, 1971
- Ron Watkins
- Â Studio Crew (uncredited) 1 episode, 1971
