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)