- Craig Littler
- Â Jason 28 episodes, 1978-1979
- Sid Haig
- Â Dragos 28 episodes, 1978-1979
- Charlie Dell
- Â Prof. E.J. Parsafoot 28 episodes, 1978-1979
- Susan Pratt
- Â Capt. Nicole Davidoff 16 episodes, 1978
- James Doohan
- Â Commander Canarvin 16 episodes, 1978
- John Russell
- Â The Commander 12 episodes, 1979
- Tamara Dobson
- Â Samantha 12 episodes, 1979
- Rosanne Katon
- Â Allegra 3 episodes, 1978
- Francine York
- Â Medusa 3 episodes, 1979
- Clete Keith
- Â Matt Daringstar 3 episodes, 1979
- John Berwick
- Â Lt. Matt Prentiss / ... 2 episodes, 1978-1979
- Julie Newmar
- Â Queen Vanessa 2 episodes, 1978
- Brendan Dillon
- Â Captain Kidd 2 episodes, 1978
- Rod Loomis
- Â Adron 2 episodes, 1979
- Angelo Rossitto
- Â Bork 2 episodes, 1978
- Heather O'Connell
- Â Heidi 2 episodes, 1979
- Udana Power
- Â Jo-Neen 1 episode, 1979
- David Comfort
- Â Karius 1 episode, 1979
- Ted Newsom
- Â Space Cadet unknown episodes
- Lou Scheimer
- Â Narrator / ... (uncredited) 28 episodes, 1978-1979
- Erika Scheimer
- Â Wiki / ... (uncredited) 12 episodes, 1978-1979
- Ram Anand
- Â Snow Monster (uncredited) 1 episode, 1978