The USS Yorktown was a Federation starship that was in service during the latter half of the 23rd century.
In 2268, the Yorktown was scheduled to deliver vaccines bound for the colony on Theta VII after a rendezvous with the USS Enterprise. (TOS: "Obsession")
In 2286, the Yorktown was under the command of Captain Joel Randolph. While deployed near the Sol system, the Yorktown was one of the many vessels disabled by the Whale probe near Earth.
In Randolph's distress call to Starfleet Command, he noted that the ship had lost all power and that all non-essential crew were given hiber-sedatives to slow down consumption of life support reserves. Meanwhile, the chief engineer attempted to deploy a makeshift solar sail so as to focus and absorb radiation from a nearby sun they were orbiting, with the hopes of generating power to keep the crew alive. (Star Trek IV: The Voyage Home)
In 2293, Tuvok's father was a Starfleet officer serving aboard the Yorktown. (VOY: "Flashback")
Yorktown personnel
Background
According to an article by Greg Jein in a 1970s fanzine regarding starship registries, he assigned the number NCC-1717 to the name Yorktown. This registry has been further propagated by being included in the writings of Michael Okuda, such as the Star Trek Encyclopedia, which also references the Yorktown as a Template:ShipClass starship. The comic book series Romulans: Schism also features the Yorktown with this number.
The Yorktown was listed as a Constitution-class starship, with the registry NCC-1704, in Franz Joseph's Star Fleet Technical Manual. However, much of the information in that manual that wasn't used on screen in some form is considered non-canon.
The USS Yorktown was the name of the central starship in Gene Roddenberry's first Star Trek proposal to NBC in 1964. The ship was named after the USS Yorktown, a World War II American aircraft carrier, which in turn was named after the last major battle of the American Revolution, won in 1781 by a combined Franco-American army commanded by Gen. George Washington.
Gene Roddenberry, in a nod to his original name choice from 1964, suggested that the Yorktown was renamed USS Enterprise-A at the end of Star Trek IV, explaining why the latter ship seemed to be launched so quickly at the end of the movie. The Next Generation fourth season writer's technical manual also indicates this to be the case. However, there is no primary evidence to confirm this theory.
The FASA sourcebook Star Trek: The Next Generation Officer's Manual lists a USS Yorktown (NCC-2033) of this era which belonged to the Template:ShipClass; the book, however, is not considered canon.
In the Star Trek: The Next Generation novel Crossover, the Yorktown is revealed to have become a museum exhibit on a starbase, but its bridge has been replaced with the original bridge of the first Enterprise. In the story in question, Captain Montgomery Scott steals the Yorktown to rescue Spock, recently captured by the Romulans, and fits it with an ancient Romulan cloaking device (the one acquired in "The Enterprise Incident"). The mission proves successful, but aid is still required from the USS Enterprise-D for Spock, Scotty and the Unification movement to escape.