Ethan Peck said it was "an incomparable honour" to be cast as the pointy-eared alien in TV show Star Trek: Discovery.
Peck, grandson of Oscar-winner Gregory, will join the show when it returns for its second season next year.
The 32-year-old celebrated by posting a photo of himself with Nimoy's family giving Spock's famous Vulcan salute.
Born in Los Angeles in 1986, Peck has experience when it comes to taking on characters associated with other actors.
