The eighth season of Stargate SG-1, an American-Canadian military science fiction television series, began airing on July 9, 2004, on the Sci Fi channel.

The eighth season concluded on February 22, 2005, after 20 episodes on British Sky One, which overtook the Sci Fi Channel in mid-season.

Season eight regular cast members include Richard Dean Anderson, Amanda Tapping, with Christopher Judge, and Michael Shanks The regular cast members of season eight are Richard Dean Anderson as Colonel/Brigadier General Jack O'Neill, Amanda Tapping as Major/Lieutenant Colonel Samantha Carter, Christopher Judge as the Jaffa Teal'c, and Michael Shanks as civilian Dr. Daniel Jackson.

Beginning with "New Order" and continuing into the spinoff series Stargate Atlantis, Torri Higginson replaced Jessica Steen as Dr. Elizabeth Weir.

After David Palffy played Anubis from seasons five through seven, the entity that made up Anubis was portrayed by Michael Shanks, Gavin Hood, Holly Ferguson, Amanda Tapping and Richard Dean Anderson in "Lockdown", by Dean Aylesworth and Rik Kiviaho in "Reckoning", and finally by George Dzundza in "Threads".

As with the two preceding seasons' finales, "Moebius" was intended to be the Stargate SG-1 series finale, and as such many actors reprised their roles from past episodes: Don S. Davis as George Hammond, Peter Williams as Apophis, Colin Cunningham as Major Davis, and Jay Acovone as Charles Kawalsky.

The main technician (played by Gary Jones), who sported the name "Norman Davis" on his uniform for seven years, was officially renamed "Walter Harriman".

[9] The team ultimately agreed on about ten initial episodes, two of which would comprise a two-hour premiere intended to address issues remaining from the season seven finale.

[3] In the first draft of "New Order, Part 1," Richard Woolsey assumed command of the SGC, but in the end the writers decided that the character of Dr. Weir suited the story better because of her background in diplomacy.

[3] The idea for "Icon" came from Damian Kindler pitching a story in season seven "in which Carter is stranded off-world, struggling to survive, while the rest of the team mounts a desperate bid to rescue her".

Airing "Affinity" first creates the minor continuity error of Daniel already knowing the name, disclosed in "Covenant", of the newly formed Trust.

[4] The writers always wanted to do a "fish out of water" story wholly dedicated to Teal'c and his attempts to fit into Earth society, but later felt that the only opportunity would have been in season one.

[4] The script of "Full Alert" called for a large military build-up and a potential worldwide confrontation, but the show's budget was limited.

Furthermore, stock shots of jets landing on aircraft carriers and missile silos opening were used to accommodate financial concerns.

Split screens with locked-off cameras and different shots with stand-in actors were used whenever possible, but still cost much time for wardrobe changes and blocking.

[3] The episode "Avatar" served as an introduction for a Stargate game that was produced at the time, and much of the story was filmed from a first-person perspective.

[12] For the scene where Carter is embedded in Replicator tiles, the model shop used cut-out vacuform pieces and slabs that had been made to fit Amanda Tapping.

[19] Although "Lockdown" was filmed mainly on the existing Stargate Command set, the story made it necessary to have the SGC broken into segregated zones.

[21] Like "Birthright" one year before, exterior scenes for "Sacrifices" were filmed at High Point Properties in Langley, British Columbia.

The Goa'uld ceremonial tent in the episode was designed to be re-usable, with the concept loosely based on the Hagia Sophia in Istanbul.

[22] "Reckoning", in which Carter attempts to open the Ancient Wall, was filmed at a sound stage at NorCo Studios, a former bicycle factory.

The ventilation is questionable, and when the director decided to add smoke for the light to catch to give a dramatic dusty air feeling, the oxygen supply decreased, which made acting harder.

[1][24] Before the season began, director Martin Wood spent a weekend at Cheyenne Mountain Complex (where the fictional Stargate Command takes place) and filmed new angles at night time, daytime, and emergency situations.

[11] Season eight was the first year that used a rear screen with an LCD projector projecting the puddle for the Stargate wormhole effect.

[9] "New Order" and "Moebius (Part 2)" both earned a 2.4 Nielsen rating, a new record high for the show during its run on cable, which has since been equalled but never beaten.

[26] The episode "Threads" originally aired as a 63-minute piece on the Sci Fi Channel, but an edited 45-minute version exists for syndication.

[27] Fans regarded "Reckoning", the climax of plots including the Goa'uld, the Replicators, and the Jaffa Rebellion, as two of the most popular episodes of the series.

The episodes "Gemini" and "Prometheus Unbound" switched sides, and "Citizen Joe" was placed after "Reckoning"/"Threads".

O'Neill's last line in "Moebius", "close enough", is an homage to The Simpsons episode "Treehouse of Horror V" that involves Homer Simpson time traveling and unintentionally making numerous changes to history; upon returning to a timeline where his family has snake tongues but everything else is otherwise normal, he says, "eh, close enough".

In "Covenant" Alec Colson, played by actor Charles Shaughnessy, is introduced to "Captain Sheffield" upon entering the Alpha Site.