Jeffrey Hunter
Christopher Pike
Acting
Leonard Nimoy
Spock
Acting
Majel Barrett
Number One
Acting
Susan Oliver
Vina
Acting
Meg Wyllie
The Keeper
Acting
Peter Duryea
Lieutenant José Tyler
Acting
Laurel Goodwin
Yeoman J. M. Colt
Acting
Clegg Hoyt
Transporter Chief Pitcairn
Acting
Malachi Throne
The Keeper (voice)
Acting
Michael Dugan
The Kaylar
Acting
Georgia Schmidt
First Talosian
Acting
Robert C. Johnson
First Talosian (voice)
Acting
Serena Sande
Second Talosian
Acting
Jon Lormer
Dr. Theodore Haskins
Acting
Adam Roarke
C.P.O. Garrison
Acting
Leonard Mudie
Second Survivor
Acting
Anthony Jochim
Third Survivor
Acting
Edward Madden
Enterprise Geologist
Acting
Robert Phillips
Orion Space Officer
Acting
Joseph Mell
Earth Trader
Acting
Janos Prohaska
Anthropoid Ape / Humanoid Bird
Acting
Carol Daniels
Bridge Crewmember (uncredited)
Crew