William Shatner
Admiral James T. Kirk
Leonard Nimoy
Mr. Spock
DeForest Kelley
Dr. Leonard 'Bones' McCoy
James Doohan
Cmdr. Montgomery 'Scotty' Scott
George Takei
Lt. Cmdr. Hikaru Sulu
Walter Koenig
Lt. Pavel Chekov
Nichelle Nichols
Lt. Cmdr. Uhura
Stephen Collins
Captain William Decker
Persis Khambatta
Lt. Ilia / The Probe
Majel Barrett
Dr. Christine Chapel
Grace Lee Whitney
CPO Janice Rand
Mark Lenard
Klingon Captain
Billy Van Zandt
Alien Boy
Roger Aaron Brown
Epsilon Technician
Gary Faga
Airlock Technician
Franklyn Seales
Crew Member
Joel Kramer
Klingon Crewman
David Gautreaux
Cmdr. Branch
John Gowans
Assistant to Rand
Howard Itzkowitz
Cargo Deck Ensign
Jon Rashad Kamal
Lt. Cmdr. Sonak
Marcy Lafferty
Chief DiFalco
Michele Povill
Lieutenant
Jeri McBride
Technician
Terrence O'Connor
Chief Ross
Michael Rougas
Lt. Cleary
Susan O'Sullivan
Woman
Ralph Brannen
Crew Member
Ralph Byers
Crew Member
Paula Crist
Crew Member
Iva Lane
Crew Member
Momo Yashima
Crew Member
Jimmie Booth
Klingon Crewman
Dave Moordigian
Klingon Crewman
Tom Morga
Klingon Crewman
Tony Rocco
Klingon Crewman
Joel Schultz
Klingon Crewman
Craig Thomas
Klingon Crewman
Edna Glover
Vulcan Master
Norman Stuart
Vulcan Master
Paul Weber
Vulcan Master
Joshua Gallegos
Security Officer
Lisa Chess
Yeoman
Leslie C. Howard
Yeoman
Sayra Hummel
Technical Assistant
Junero Jennings
Technical Assistant
Bill McIntosh
Klingon Crewman (as Bill McTosh)
Doug Hale
Enterprise Computer (voice)
David Armstrong
Enterprise Crew Member (uncredited)
Richard Arnold
Crew Member (uncredited)
Rosanna Attias
Enterprise Crew Member (uncredited)
Jerry Best
Enterprise Sciences Crew Member (uncredited)
Christopher Doohan
Extra (uncredited)
Fred Bronson
Enterprise Crew Member (uncredited)
Bob Bryan
Enterprise Crew Member (uncredited)
Robert Buckingham
Enterprise Crew Member (uncredited)
Celeste Cartier
Enterprise Crew Member (uncredited)