The ninth season of Stargate SG-1, an American-Canadian television series, began airing on July 15, 2005, on SCI FI. The ninth season concluded on March 10, 2006, after 20 episodes on the same channel. The series was originally developed by Brad Wright and Jonathan Glassner, and Brad Wright, Robert C. Cooper, Joseph Mallozzi and Paul Mullie served as executive producers. The season arc centers on the new threat of the Ori, a race who Daniel Jackson and Vala Mal Doran unleash in an unknown galaxy, and who are threatening to prepare for a crusade into the Milky Way galaxy to convert the beings to their religion called Origin.

Stargate 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 final episode first aired on Sky1 on March 13, 2007.