USS Enterprise is a series of starships in the Star Trek media franchise. Enterprise is the main setting of the original Star Trek television series (1966–69), nine Star Trek films, and Star Trek: Strange New Worlds (2022–present). The vessels carry their crew on a mission "to explore strange, new worlds; to seek out new life and new civilizations; to boldly go where no man has gone before."

Matt Jefferies designed the Enterprise for television, and its core components – a flying saucer-shaped primary hull, two offset engine nacelles, and a cylindrical secondary hull – persisted across several television and film redesigns. The vessel influenced the design of subsequent franchise spacecraft, including other vessels named Enterprise, and the model filmed for the original Star Trek TV series has been on display for decades at the National Air and Space Museum.

Initially a vision of the potential for human spaceflight, the Enterprise became a popular culture icon. The Enterprise has repeatedly been identified as one of the best-designed and most influential science fiction spacecraft.

Series creator Gene Roddenberry reviewed hundreds of science fiction magazines, dating back to 1931, to gather ideas about what he wanted Star Trek's main vessel to look like. Despite the research, he was more confident in what he did not want than what he did want. He set several parameters:

We're [...] out in deep space, on the equivalent of a cruiser-size spaceship. We don't know what the mode of power is, but I don't want to see any trails of fire. No streaks of smoke, no jet intakes, rocket exhaust, or anything like that [...]. It will be like a deep space exploration vehicle, operating throughout our galaxy.

Roddenberry further specified that the ship would have a crew of 100–150 and be incredibly fast. Art director Pato Guzman's assistant, Matt Jefferies, was responsible for designing the ship and several of its sets. Jefferies and Roddenberry did not want the vessel to look like any of the rocket ships already used by the aerospace industry or in popular culture; many designs were rejected for being "too conventional". To meet Roddenberry's requirement that the ship look believable, Jefferies tried "to visualize what the fourth, fifth or tenth generation of present-day equipment would be like". Jefferies' experience with aviation let him imbue his designs with what he called "aircraft logic". He imagined the ship's engines would be too powerful to be near the crew, requiring them to be set apart from the hull. Jefferies initially rejected a disk-shaped component, worried about the similarities to flying saucers; however, a spherical module eventually flattened into a disk. Because the ship would be expected to flash by quickly on television screens, Jefferies wanted the design to be "very simple, but immediately identifiable – a shape that you could instantly pick out."

During a visit with Jefferies, Roddenberry and NBC staff were drawn to a sketch of the ship resembling its final configuration. Jefferies had created a small model of this design that, when held from a string, hung upside-down – an appearance he had to "unsell". He kept the hull smooth, with a sense that the ship's components were serviced from inside. He designed the Klingon starship seen in the third season by rearranging and changing the shape of Enterprise's basic modules: a main body, two engine pods, and a neck with a head on it. Some of Jefferies' rejected design concepts – such as spherical hull sections and warp engines that encircle a ship – inspired future Star Trek vessel designs.

The Enterprise was originally named Yorktown, but Roddenberry was fascinated by the aircraft carrier Enterprise and had "always been proud of that ship and wanted to use the name." The NCC-1701 registry stems from NC being one of the international aircraft registration codes assigned to the United States. The second C was added because Soviet aircraft used Cs, and Jefferies believed a venture into space would be a joint operation by the United States and Russia. Jefferies rejected 3, 6, 8, and 9 as "too easily confused" on screen; he eventually reasoned the Enterprise was the first vessel of Starfleet's 17th starship design, hence 1701. The Making of Star Trek explains that USS means "United Space Ship" and that "Enterprise is a member of the Starship Class". Licensed texts, on-screen graphics, and dialogue later describe the ship as a Constitution-class vessel.