From Stargate Wiki
- "...somewhere far, far away."
- — Cameron Mitchell
The Ori galaxy is the the home galaxy of the Ori and the Alterans as well as various groups of humans. The location of this galaxy is unknown but appears to be very far away from the Local Group, so far that travel between the two in hyperspace would take years. (SG1: "Avalon, Part 2", "Camelot")
The Ori and the Alterans once evolved on Celestis here in this galaxy as one race. Over time the Alterans developed advanced technology and fled the galaxy to escape prosecution and execution from their more religious fanatic Ori brethren. The Ori continued to evolve and eventually ascended and lived on a higher plane of existence. (SG1: "Avalon, Part 2", Stargate: The Ark of Truth)
The Ori created a race of humans and spread them on many worlds. They created Origin to enforce their laws on the lower planes and to have the masses worship them as gods. This gave them more power which they sapped from their followers. They created the Priors and the Doci to serve as their pawns in spreading Origin and creating more power. When they discovered the galaxy that the Alterans went to they sent Priors to convert more people and then sent ships to attack, in an effort to gain more power and once and for all destroy the Ancients. (SG1: "Origin", "The Fourth Horseman, Part 1", "The Fourth Horseman, Part 2")
SG-1 took the Odyssey to this galaxy to search for the Ark of Truth, an Ancient device capable of making the Ori followers believe that the Ori were not gods, thus losing most of their power. The Ark was activated and used on the Doci which spread to all the Priors and then out to all the human followers. (Stargate: The Ark of Truth)