Yesteryear

William Shatner

James T. Kirk (voice)

Leonard Nimoy

Spock (voice)

DeForest Kelley

Leonard McCoy (voice)

George Takei

Hikaru Sulu (voice)

Nichelle Nichols

Uhura (voice)

James Doohan

Montgomery Scott (voice)

Majel Barrett

Christine Chapel / Starfleet Computer (voice)

Mark Lenard

Sarek (voice) (uncredited)

Billy Simpson

Young Spock (voice) (uncredited)

Keith Sutherland

Young Sepek (voice) (uncredited)