Spock his full Vulcan name generally considered unpronounceable by most Humans – was a Human/Vulcan hybrid (the son of Ambassador Sarek of Vulcan and Amanda Grayson an Earthwoman) who became one of the most distinguished and respected figures in the United Federation of Planets in his lifetime.

As a Starfleet officer in the latter half of the 23rd century, he served aboard the starship USS Enterprise as science officer under Captain Christopher Pike, as first officer and science officer under Captain James T. Kirk, and as the Enterprise's commanding officer during her tenure as a training vessel. In the 24th century, Spock became a celebrated ambassador and adviser to the Federation's leadership.

Spock was commissioned as a Starfleet officer in the early 2250s with the serial number S 179-276 SP, and held an A7 computer expert classification. By 2254, he was assigned to the USS Enterprise. The starship and her namesake were his home for nearly forty years, until 2293.

Spock's service under Pike (eleven years, four months, and five days) inspired considerable respect and loyalty from the young officer. In 2267, Spock risked his life and career for the sake of his former captain.

After Pike's promotion to fleet captain, James T. Kirk assumed command of the Enterprise in 2265.

When Kirk was court-martialed for causing the death of Lieutenant Commander Ben Finney, Spock proved that the Enterprise's computer tapes had been altered by Finney to frame Kirk and proved his existence on Enterprise with a heatbeat monitor.

After the Enterprise's five-year mission of exploration was completed, Spock chose to return to his home planet of Vulcan. As a result of his occasional displays of emotion during his Enterprise missions, he decided to undergo the kolinahr ritual to purge himself of the last vestiges of emotion. Spock aborted this training and resumed his Starfleet career both for personal reasons and to help Admiral James T. Kirk during the V'Ger incident. see Star Trek: The Motion Picture

Sometime after the V'Ger incident, Spock was promoted to captain and assigned to Starfleet Academy, where he trained cadets on the Enterprise, which had been retired from active service.

The Enterprise-A

Prior to the launch of the new Enterprise, Spock was recruited to test the new brig as he was the most intelligent and resourceful person the designers could find. However, despite his ingenuity, he failed to escape.