Stargate SG-1 (often stylized in all caps, or abbreviated SG-1) is a military science fiction adventure television series within Metro-Goldwyn-Mayer's Stargate franchise. The show, created by Brad Wright and Jonathan Glassner, is based on the 1994 science fiction film Stargate by Dean Devlin and Roland Emmerich. The television series was filmed in and around the city of Vancouver, British Columbia, Canada. The series premiered on Showtime on July 27, 1997, and moved to the Sci Fi Channel on June 7, 2002; the series finale aired on Sky1 on March 13, 2007.

The story of Stargate SG-1 begins about a year after the events of the feature film when the United States government learns that an ancient alien device called the Stargate can access a network of such devices on a multitude of planets and in space. SG-1 is an elite United States Air Force special operations team, one of about 20 teams from Earth who explore the galaxy and defend against alien threats such as the Goa'uld, the Replicators and the Ori. The series draws upon Egyptian, Greek and Norse mythology, as well as the legend of King Arthur.

The series was a ratings success for its first-run broadcasters and in syndication and was particularly popular in Europe and Australia. Stargate SG-1's awards include eight Emmy nominations. It also spawned the animated television series Stargate Infinity, the live-action spin-off TV series Stargate Atlantis, Stargate Universe, and Stargate Origins and the direct-to-DVD films Stargate: The Ark of Truth and Stargate: Continuum. Merchandise for Stargate SG-1 includes games and toys, print media and an original audio series.