Leonard Nimoy

Nimoy studied acting in Boston before moving to Los Angeles as a young man, working steadily but without major recognition in television guest roles throughout the 1950s and early 60s before his career-defining casting.

He nearly didn't return as Spock at all after publicly souring on the role — until Paramount offered him more money, more control, and a genuinely emotional arc to play. He wrote a memoir titled I Am Not Spock partway through his career reflecting his complicated feelings about being so closely identified with the character.

He later wrote a follow-up titled I Am Spock after making peace with the role, and he also directed two later entries in the franchise himself, becoming one of the few actors in the series to move behind the camera.