- Gil Gerard as Capt. William "Buck" Rogers
- Erin Gray as Col. Wilma Deering
- Thom Christopher as Hawk
- Jay Garner as Admiral Efram Asimov
- Wilfrid Hyde-White as Dr. Goodfellow
- Tommy Madden as General Xenos
- Felix Silla as Twiki
- Mel Blanc as Voice of Twiki
- Alex Hyde-White as Ensign Moore
- John Edward Allen as General Zoman
- Tony Cox as Private Zedht
- Billy Curtis as General Yoomak
- Harry Monty as General Sothoz
- Spencer Russell as General Towtuk
- Charles Secor as General Kuzan
- Jeff David as Voice of Crichton (uncredited)