Ed Bishop
— Cmdr. Ed Straker
George Sewell
— Col. Alec Freeman
Michael Billington
— Col. Paul Foster
Wanda Ventham
— Col. Virginia Lake
Vladek Sheybal
— Dr. Doug Jackson
Derren Nesbitt
— Craig Collins
David Warbeck
— Skydive Commander
Shane Rimmer
— Lt. Bill Johnson / Alien / CIA Agent
Deborah Grant
— Linda Simmonds
Patrick Allen
— Turner