Star Trek: Enterprise, originally titled simply Enterprise for its first two seasons, is an American science fiction television series created by Rick Berman and Brannon Braga. It originally aired from September 26, 2001 to May 13, 2005 on UPN. The sixth series in the Star Trek franchise, it is a prequel to Star Trek: The Original Series. Set in the 22nd century, a hundred years before the events of The Original Series, it follows the adventures of the Enterprise, Earth's first starship capable of traveling at warp five, as it explores the galaxy and encounters various alien species.

Following the culmination of Star Trek: Deep Space Nine and with Star Trek: Voyager scheduled to end, Paramount asked Braga and Berman to create a new series to continue the franchise. Rather than setting it in the 24th century alongside Deep Space Nine and Voyager, they decided to set it in an earlier period, allowing them to explore new parts of the Star Trek fictional universe. Wanting a more basic, relatable, character-driven series, Berman and Braga concentrated on a core trio: Captain Jonathan Archer (played by Scott Bakula), Commander Trip Tucker (Connor Trinneer), and Sub-commander T'Pol (Jolene Blalock).

The show broke with Star Trek convention in several ways. In addition to dropping the Star Trek prefix, Enterprise used the pop-influenced song "Faith of the Heart" (performed by Russell Watson) as its theme. It was filmed on the Paramount lot in Los Angeles, California, on the same stages that housed the Star Trek series and films since the abandoned Star Trek: Phase II in the late 1970s.

The first two seasons were characterized by stand-alone episodes that explored topics like humanity's early relations with the Vulcans, and first encounters with the Klingons and Andorians, aliens already familiar to franchise viewers. Seeking to attract a wider audience, UPN called for changes for Enterprise's third season. It was renamed Star Trek: Enterprise, and was changed to focus on action-driven plots and a single, serialized storyline: the crew's mission to prevent the Earth being destroyed by a newly introduced alien species, the Xindi. In 2005, UPN cancelled the series after its fourth season, despite a fan-led campaign to continue it. It was the first time in 18 years that no new Star Trek television series episodes would be produced, the beginning of a hiatus that lasted until the launch of Star Trek: Discovery in 2017, another prequel to Star Trek: The Original Series and chronological sequel to Enterprise.