The 2290s decade covers the period from 2290-2299.
The year 2293 was particularly significant in this decade, as it marked the ending of hostilities between the United Federation of Planets and the Klingon Empire, despite attempted thwarting by a conspiracy to disrupt the peace negotiations at Camp Khitomer. Additionally, the crew of the USS Enterprise-A were retired following the signing of the Khitomer Accords, along with the Enterprise-A herself. Captain James T. Kirk was presumed killed in this year during the maiden voyage of the USS Enterprise-B. (Star Trek VI: The Undiscovered Country; Star Trek Generations)
- Following the explosion of the Klingon moon Praxis, the Federation and the Klingon Empire begin negotiations for ending nearly seventy years of hostilities between the two governments. Chancellor Gorkon of the Klingon High Council is assassinated on route to Earth, threatening the peace initiative. An investigation by the crew of the Enterprise-A reveals a conspiracy to stop the peace process, and subsequently manages to arrest the conspirators, allowing the Khitomer Accords to be signed in 2293. (Star Trek VI: The Undiscovered Country)
- Captain Spock meets Ambassador Pardek at the Khitomer Conference and the two begin discussions of reunification of the Vulcan and Romulan peoples. (TNG: "Unification I")
- The crew of the Enterprise-A is retired with their vessel in 2293. The USS Enterprise-B is launched later that year. (Star Trek VI: The Undiscovered Country); (Star Trek Generations)
- The Federation starship USS Jenolan crashes on a Dyson sphere in 2294, killing all but two passengers. Only Captain Montgomery Scott is recovered seventy-five years later. (TNG: "Relics")