The 23rd century, defined in the calendar of Earth as being from 2201 until 2300, was a period of expansion for the Federation, with Humans and other founding species, such as Vulcans, at the forefront of exploration. The long-running conflict with the Klingons, begun in the 22nd century, was a major topic of this century's history, as was the rekindling of tensions with the Romulans. Of particular note are the voyages of the starship Enterprise and the careers of its long-serving command staff under James T. Kirk.
- 2223: Relations between the Federation and the Klingon Empire degenerate starting a tense cold war.
- 2243: The duotronic computer is invented by Doctor Richard Daystrom, becoming the primary computing platform for all Starfleet vessels for the following eighty years. (TOS: "The Ultimate Computer")
- 2245: The Federation starship USS Enterprise is launched. (TAS: "The Counter-Clock Incident")
- 2265: The El-Aurian homeworld is destroyed by the Borg. (TNG: "Q Who")
- 2267: Federation-Klingon relations improve with the signing of the Treaty of Organia. Together with the Romulan Star Empire the two powers also establish a "colony of galactic peace" on Nimbus III. (TOS: "Errand of Mercy"; Star Trek V: The Final Frontier)
- 2272: An attack on Earth by a massive machine lifeform called V'Ger is closely averted. (Star Trek: The Motion Picture)
- 2286: Earth is again saved from being obliterated by a probe of unknown origin. (Star Trek IV: The Voyage Home)
- 2293: Despite the prior assassination of Klingon Chancellor Gorkon, the Khitomer Accords between the Federation and the Klingon Empire are signed on the Khitomer Conference to establish a lasting peace between the two powers. (Star Trek VI: The Undiscovered Country)
Events without year specification
- By the late 23rd century, the tribble species is eradicated by the Klingons. (DS9: "Trials and Tribble-ations")
- Cloaking devices are installed aboard Klingon starships such as the IKS Klothos. (DS9: "Once More Unto the Breach")
- An alternate approach to the transporter, the Elway Theorem, is first tested in this century. Instead of utilizing subspace as the medium for which matter and energy are transported from one location to another, this form of transporting uses dimensions of space. In the end, this approach is rejected as fatal for the subject and being not as nearly as accurate as the transporter. (TNG: "The High Ground")
- Late 23rd century to Early 24th century: Sometime between 2267 and 2270, Spock becomes commander-in-chief of the Terran Empire and implements several major reforms, turning the Empire into a more peaceful and less aggressive power. Prior to the full enactment of these reforms, the Terran Empire forces occupy Bajor. Spock's reforms leave the Empire unprepared to fight against the Klingon-Cardassian Alliance. The Alliance conquers the entire Terran Empire, enslaving the Terrans and Vulcans. (DS9: "Crossover")
23rd century productions
- Star Trek: The Original Series
- Except for "Assignment: Earth"
- Star Trek movies:
- DS9: "Trials and Tribble-ations" (in part)
- VOY: "Gravity" (in part)
|22nd century||Timeline||24th century|