The starship commanded by Captain Kirk in the original Star Trek films is the USS Enterprise. It is the legendary Constitution-class vessel associated with Kirk, Spock, McCoy, and the original crew.
Kirk commands the original USS Enterprise, registry NCC-1701, in Star Trek: The Motion Picture and in the early portion of Star Trek II: The Wrath of Khan. After the ship is severely damaged and later destroyed in Star Trek III: The Search for Spock, Kirk receives command of a successor vessel.
That replacement is the USS Enterprise-A, which appears in Star Trek IV, Star Trek V, and Star Trek VI. Both ships carry the Enterprise name, so the broader quiz answer “USS Enterprise” is the canonical name readers normally expect. The registry distinguishes the original vessel from its successor.
The Enterprise was commissioned in 2245 and was originally commanded by Robert April, followed by Christopher Pike. Kirk then led it during the original television era and its film adventures, making the ship as central to Star Trek’s identity as its human characters.