Here's what happened to Spock after Star Trek: The Original Series and the Star Trek movies that starred the classic crew. For 47 years, the late Leonard Nimoy donned the half-Vulcan's signature pointed ears and portrayed Mr. Spock throughout The Original Series, Star Trek: The Animated Series, the first six Star Trek movies, as well as a guest appearance on Star Trek: The Next Generation. Nimoy reprised the role in J.J. Abrams' first two Star Trek reboot movies, with his final appearance as the Vulcan in Star Trek Into Darkness in 2013.
Spock is the signature character of the Star Trek franchise; two younger versions of Spock have been portrayed by Zachary Quinto in the Abrams trilogy and by Ethan Peck on Star Trek: Discovery, but they both follow the path Nimoy trailblazed. Nimoy's original Spock was the First Officer/Science Officer aboard the Starship Enterprise under Captain James T. Kirk (William Shatner). Spock was promoted to Captain and commanded the Enterprise himself before he sacrificed his life to stop Khan (Ricardo Montalban) in Star Trek II: The Wrath of Khan. After Spock's resurrection in Star Trek III: The Search for Spock (which was directed by Nimoy), the Vulcan stood by Kirk throughout the next three Star Trek movies, which would be their final adventures together.
After the events of Star Trek VI: The Undiscovered Country, Spock wasn't aboard the U.S.S. Enterprise-B in 2293 when Kirk was presumed killed by the ship's encounter with the Nexus. He would not see his old friend again as Kirk actually died in 2371 at the conclusion of Star Trek Generations, but Spock would later encounter a younger Kirk (Chris Pine) in the alternate Kelvin timeline he inadvertently helped create in Star Trek 2009.
Spock Became An Ambassador After Starfleet
In his post-Starfleet life, Spock followed in the footsteps of his father Sarek (Mark Lenard) and became a Federation ambassador. Spock's diplomatic career actually started in Star Trek VI; after the Klingon moon Praxis exploded, Spock became the Federation's Special Envoy and opened peace talks with High Chancellor Gorkon (David Warner). At the Khitomer conference that forged the peace between the Klingons and the Federation, Spock commenced diplomatic talks with Pardek of Romulus, in an attempt to foster a unity between the Vulcans and the Romulan Empire, who share genetic origins.
Since Vulcans are incredibly long-lived, Spock remained a diplomat for several decades. In 2368, Ambassador Spock continued his clandestine attempts at Vulcan/Romulan unification and he met Star Trek: The Next Generation's Captain Jean-Luc Picard (Patrick Stewart) on Romulus. A year later, Spock got involved when Counselor Deanna Troi (Marina Sirtis) was kidnapped by the Romulans, using "cowboy diplomacy" to help safety return Troi to the Enterprise-D.
Star Trek: The Next Generation's "Unification" two-parter and Star Trek VI released in November and December 1991 to commemorate Star Trek's 25th anniversary. It was only fitting that Spock played major roles during both events celebrating the franchise.
Spock In The Kelvin Timeline
As seen in Star Trek 2009, Ambassador Spock tried to use red matter to save Romulus from their star going supernova in 2387 but he and the Romulan starship commanded by Nero (Eric Bana) were pulled into a black hole and thrown backwards in time to the 23rd century. Nero's arrival in 2233 led to the destruction of the U.S.S. Kelvin, the death of Kirk's father George (Chris Hemsworth), and the creation of the alternate Kelvin timeline.
Ambassador Spock arrived in the Kelvin timeline 25 years later to watch Nero destroy Vulcan; he then helped the younger Kirk return to the Enterprise so he could take command and ultimately defeat Nero. At the end of Star Trek 2009, Ambassador Spock met his younger self as he set about to help create a colony for the surviving Vulcans. In Star Trek Into Darkness, the younger Spock later called upon Ambassador Spock for guidance in how to defeat Khan (Benedict Cumberbatch).
Sadly, Spock died of natural causes in New Vulcan in 2263 during the events of Star Trek Beyond. Though Leonard Nimoy's version of the Vulcan died only 33 years after his date of birth in the Prime timeline, Ambassador Spock was 162 years old chronologically when he passed away in the Kelvin timeline. Considering his long life and the number of times he saved the galaxy in multiple eras, Nimoy's Spock is easily the most pivotal character in Star Trek. To paraphrase Kirk's admiration of his logical best friend in Star Trek Beyond, "Spock, what would Star Trek do without you?"