Tuvok entered Starfleet Academy in 2289 at his parents' insistence. His mother and father were Starfleet officers and both served aboard the Excelsior-class U.S.S. Yorktown. Upon graduation in 2293 Tuvok was assigned to the U.S.S Excelsior as a junior science officer under the command of Captain Hikaru Sulu. Soon after, the crew of the Excelsior encountered a subspace shock wave resulting from the accidental destruction of the Klingons' chief energy-producing moon, Praxis. A short while later Klingon Chancellor Gorkon was assassinated and Captain James Kirk and Dr. McCoy were accused of the crime and were taken to the Klingon Homeworld to be tried. Against Starfleet orders, Captain Sulu decided to mount a rescue of Kirk and McCoy. Ensign Tuvok confronted Captain Sulu about the breach of orders but to no avail. To conceal their approach to Qo'noS, Sulu ordered the Excelsior through the Azure Nebula, and it was there that he encountered a Klingon Battle Cruiser commanded by Captain Kang. In the ensuing battle, junior science officer Dmitri Valtane was fatally injured. It was at this time that a memory engram virus left Valtane's brain and entered Tuvok's. The virus would remain in Tuvok until 2373. To evade Kang, Sulu ordered that the volatile sirillium in the nebula be ignited. After escaping the Klingons, Captain Sulu reconsidered the situation and aborted the rescue mission. Captain Sulu and the Excelsior later played a key role in the Khitomer Peace Conference of 2293 by assisting the U.S.S. Enterprise-A in its battle with General Chang's prototype Bird-of-Prey and by preventing the assassination of Klingon Chancellor Azetbur. ("STAR TREK VI: The Undiscovered Country", "Flashback" [VGR]).

   His experiences at the Academy and aboard the Excelsior were not pleasant for him and so Tuvok left Starfleet in 2298, returning to Vulcan to undergo the Kolinahr. In 2304, before completion of the Kolinahr, Tuvok entered pon farr. Thereupon he met T'Pel, whom he married. Tuvok and T'Pel had four children, three sons and a daughter. T'Pel was in labor for 96 hours during the birth of their third child. While on Vulcan during this period, Tuvok taught archery science for several years at the Vulcan Institute of Defensive Arts. ("Basics, Part II" [VGR]).

   After raising a family of his own, Tuvok appreciated his parents' motives for sending him to Starfleet. So after a 51 year absence, Tuvok returned to Starfleet in 2349 and was assigned to the U.S.S. Wyoming. ("Flashback" [VGR]). Two years later, in 2351, Tuvok transferred off of the U.S.S. Wyoming and became an instructor at Starfleet Academy. He taught there for sixteen years, until 2367. In 2365 while still an Academy instructor, Tuvok met a starship commander who would figure prominently in his life for years to come. After analyzing recent mission logs of Kathryn Janeway, he felt it necessary to dress her down in front of three Admirals for not following security protocols during her previous space voyage. She took the lesson in stride and the two later became good friends. ("Revulsion" [VGR]). In 2367, Lieutenant Junior Grade Tuvok left his teaching position at Starfleet Academy and his new assignment was tactical officer aboard the U.S.S. Billings. The next year, the ship's executive officer was transferred from the ship and was replaced by Commander Kathryn Janeway. ("Night" [VGR]). Over the next several years, Tuvok would serve as Kathryn Janeway's tactical officer and the two would form a lasting friendship, with Tuvok becoming Janeway's confidante and most trusted advisor. In 2370, Tuvok was temporarily stationed at the Jupiter station. While there he kept in contact with Kathryn Janeway via written letters. ("Tuvix" [VGR]).

   In 2371, on stardate 48038.5, the U.S.S. Voyager (NCC-74656), an Intrepid-class starship, was launched under the command of Captain Kathryn Janeway. Lieutenant Tuvok was assigned as the ship's tactical officer. That same year, some months before stardate 48315.6, Lieutenant Tuvok began an undercover mission to infiltrate a Maquis cell of which Chakotay and B'Elanna Torres were members. Some months later while pursuing a Maquis ship in the Badlands, the U.S.S. Voyager was drawn into the Delta-Quadrant of the galaxy, some 70,000 light years from Federation space, by a powerful being. Starfleet believed the ship to be destroyed in the Badlands. ("Caretaker" [VGR]). Although he didn't openly admit it to anyone, Tuvok missed his wife and children greatly while he was stranded in the Delta Quadrant. On stardate 48734.2, a member of the Komar species took control of Tuvok in an attempt to lead Voyager into a dark-matter nebula so that the Komar could extract the crew's neural energy. The crew prevented the Komar's plans and Tuvok was restored to normal. ("Cathexis" [VGR]).

   In 2372, after Voyager crewman Lon Suder commited murder, Tuvok mind melded with him in order to understand his motives. Suder became much more stable and centered as a result of the meld, but unfortunately, Tuvok acquired Suder's violent emotions and he had difficulty purging them. ("Meld" [VGR]).

On Stardate 49655.2, a transporter mishap caused Lieutenant Tuvok and Neelix to become fused at the genetic level. The resultant being adopted the name Tuvix and became a part of the crew for two weeks. The Emergency Medical Hologram aboard the Voyager discovered a way to separate Tuvix into Tuvok and Neelix. Tuvix refused to undergo the separation process because he did not wish to die. Captain Janeway ultimately compelled him to, and Tuvok and Neelix were restored. ("Tuvix" [VGR]).

   In 2373, the memory engram virus that entered Tuvok's brain in 2293 following Dmitri Valtane's death, resurfaced when the U.S.S. Voyager encountered a nebula that looked just like the Azure Nebula. The Voyager's holographic doctor successfully destroyed the virus with thoron radiation. ("Flashback" [VGR]).

   In early 2374, on Stardate 51186.2, Captain Kathryn Janeway promoted Tuvok to the rank of Lieutenant Commander. ("Revulsion" [VGR]).

   In 2375, on Stardate 52438.9, Tuvok's commitment to his wife and his control of his emotions were put to the test. Tuvok and Tom Paris' shuttle passed through a subspace sinkhole and became stranded on an inhospitable Class-D planet within. There he met Noss, a woman space pilot who was also stranded there. Even after several months on the barren rock with almost no hope of rescue, Tuvok avoided Noss' attempts at forming a romantic relationship. The crew of the Voyager eventually rescued them all, and Noss was delivered back to her homeworld. ("Gravity" [VGR]).

    Around this time, Tuvok started to experience lapses in concentration and Voyager's Doctor diagnosed him with a degenerative neurological condition which could only be cured via a special mind meld with a compatible Vulcan. Tuvok began periodic treatments for the malady which he choses to keep a secret from Captain Janeway and the crew. If not cured, the condition's symptoms will become serious and untreatable in several years time. ("Endgame, Part II" [VGR]).

   On stardate 53263.2, while returning to the U.S.S. Voyager aboard the Delta Flyer in 2376 with Neelix, Tuvok was attacked by a Ba'Neth intruder. The alien used a weapon against Tuvok which sent him into a neuroleptic shock induced coma. Aboard the Voyager the Doctor determined that Tuvok had received severe damage to his brain's cognitive, memory and logic centers. Neelix began trying to awaken the Vulcan by stimulating his senses of smell and hearing with incense, music and conversation. After several hours, Tuvok regained consciousness, but he was a shell of the person he had been before. The new Tuvok was less intelligent and more emotional. He became despondent after learning about the man he had once been and might never be again. The crew searched for information about the weapon that shorted out Tuvok's brain in the hopes of deriving a treatment, while Neelix dealt with the possibility that Tuvok may remain as he was. Neelix took Tuvok under his wing and the two became good friends. They soon discovered that Tuvok had a flair for making desserts. When the Ba'neth were finally contacted, the Doctor created a treatment based upon the details of the Ba'neth weapon, but Tuvok was reluctant to have the treatment after realizing that when returned to normal, he would no longer have fun or smile or be Neelix's friend. Neelix convinced him to undergo the treatment, and Tuvok was returned to normal. It was not immediately clear whether Tuvok was changed by this brief but profound experience. ("Riddles" [VGR]).

    In late 2376, the Borg Queen learned of a dreamlike realm within the Collective called Unimatrix Zero where a small number of errant drones could meet and experience life as an individual while they were in their regeneration cycles, and she planned to crush the Borg rebellion by demolishing Unimatrix Zero. ("Unimatrix Zero, Part I" [VGR]).

    Then, in early 2277, on stardate 54014.4, Janeway decided to take a team into the Collective in order to implement a special nanovirus which would enable the rebel drones to remember their time in Unimatrix Zero upon awaking from their regeneration cycles. Janeway, Tuvok and B'Elanna Torres entered a Borg Cube and allowed themselves to be assimilated as drones, trusting that the neural suppressant they were injected with on Voyager would keep their implants from really connecting them to the Collective. While there, Seven of Nine aboard Voyager entered Unimatrix Zero to aid the drones there.

    Just as Janeway's away team approached the Central Plexus and readied to download the virus, Tuvok's neural suppressant wore off and he received telepathic communication from the Borg Queen which prompted him to stop Janeway and Torres. They successfully inserted the virus into the system, but Tuvok helped the Borg capture Janeway and Torres.

    When the nanovirus acted, the rebel drones awakened from regeneration with full memories and soonafter, a Borg sphere commanded by a freed Klingon drone, Korok, showed up and attacked the Queen's Borg Cube. Tuvok, Janeway and Torres were beamed back to Voyager just as the Cube exploded. The Doctor removed the trio's implants and returned them all to normal, but Tuvok had memories of being a Borg drone who had been forced to act against his friends. ("Unimatrix Zero, Part II" [VGR]).

    Later in 2377, on stardate 54238.3, while the U.S.S. Voyager crew was busy helping free Harry Kim, Seven of Nine and the Doctor from captivity aboard a Lokirrim patrol ship, Tuvok entered pon farr and had to be ministered to by Tom Paris in the Doctor's absence. But deep meditation and special drug therapy did little to alleviate the mating instinct in Tuvok, so he decided to satisfy the drive by being with a holographic representation of his wife T'Pel in the ship's holodeck. ("Body and Soul" [VGR]).

    In late 2377, on stardate 54973.4, the U.S.S. Voyager crew was visted by Admiral Kathryn Janeway who had traveled back in time from the year 2404 to help them get home earlier. Using the technology brought by Admiral Janeway, Captain Janeway and her crew entered a huge Borg transwarp hub to destroy it. Admiral Janeway allowed herself to be assimilated by the Borg Queen and thus infecting the collective with a neurolytic pathogen. Then when the hub's shielding went down, the huge complex of interspatial manifolds and transwarp conduits was destroyed. The Starship Voyager used one of the conduits to travel home, and the ship was met by several Starfleet vessels and escorted home to Earth. Shortly after returning to the Alpha Quadrant, Tuvok traveled to Vulcan and underwent a fal-tor-voh mind meld with one of his children to cure his neuroglogical condition. ("Endgame, Parts I and II" [VGR]).