Stargate refers to the science fiction media franchise beginning with the 1994 feature film Stargate, and the subsequent body of works that detail an elaborate fictional universe. The story of the film was continued in novel form, in two live-action television series (Stargate SG-1 and Stargate Atlantis), one animated series (Stargate Infinity), and in other derivative works.

Owned by MGM, the franchise has proved successful even 12 years after its conception. However, due to multiple developers working separately and independently on the franchise over the years, as a whole, the various Stargate productions are not entirely coherent. Although no set of works form a "correct" canon, the largest fanbase exists for the story which begins with the original film, and continues with Stargate SG-1 (1997-Present) and Stargate Atlantis (2004–Present).

All Stargate productions centre around the premise of a "Stargate", a ring-shaped alien device that allows for personal teletransportation to complementary devices cosmic distances away.Despite being completely fictional, most Stargate productions are set in the present day, with plots constructed so that there is no immediate contradiction between the depicted events and reality.As such, the existence of the Stargate devices is described as a military secret.

In the story, most Earth mythologies are explained as based upon events involving aliens who visited or controlled Earth civilizations in the distant past. Most significantly an alien race (later known in SG-1 as the Goa'uld) enslaved the inhabitants of ancient Egypt, creating its culture and religion.Posing as Gods, they made slaves of humans, and used Stargates to move labourers from Earth to other habitable planets. However, after a successful rebellion the aliens were forced to flee and the Stargate was buried, to be forgotten until rediscovery in 1928.