Stargate SG-1 (often abbreviated as SG-1) is an American-Canadian science fiction television series, part of the Stargate franchise. Its story begins one year after the events of the 1994 science fiction film Stargate. It was produced in and around Vancouver, Canada.

In the Stargate science fiction universe, a network of ancient alien devices called Stargates connects the far reaches of several galaxies, including the Milky Way, Pegasus and Ori galaxies, opening the door for near-instantaneous interstellar travel. The Stargates often use a DHD or Dial-Home Device, almost always referred to as the "DHD" control consoles, to operate the dialing sequence of the various Stargates. Stargate SG-1 chronicles the exploits of SG-1, the "flagship team" of at least 25 teams who explore the galaxy and defend Earth against alien threats such as the Goa'uld, Replicators and later the Ori.