In the episode "Sight Unseen", Col. Jack O'Neill tells paranoid veteran Vernon Sharpe (Jody Racicot), who sees aliens, that they were from "Melmac". When Sharpe asks, "Isn't that where ALF was from?" O'Neill says he never saw the show. This is an in-joke, since for most of its run, "ALF" (1986) was in the same time slot as "MacGyver" (1985), which starred Richard Dean Anderson in the title role.
Richard Dean Anderson (Jack O'Neill) executive-produced and starred in his favourite project to date, the critically acclaimed "Legend".
In the episode "Secrets", Col. O'Neill tells a reporter "That's O'Neill, with two L's. There's another Colonel O'Neil with one L. He has no sense of humor." In the feature film Stargate (1994), the lead character, whose name was spelled with one L, was played by 'Kurt Russel' and was a much more humorless character.
In Stargate SG-1, Amanda Tapping plays an Air Force scientist who explores other worlds through the stargate. On an episode of "Due South" (1994), she guest starred as an Air Force scientist who was apparently studying UFO's on Earth.
Amanda Tapping (Samantha Carter) has guest starred on such series as "The X-Files", "Due South", "Millennium" and "The Outer Limits".
Michael Shanks (Daniel Jackson) has guest-starred on "The Outer Limits".
Christopher Judge (Teal'c) has guest-starred on "MacGyver".
Kasuf and Skaara are played by the same actors who portrayed them in the movie.
Although they wrote the original Stargate (1994) feature the series is based on, Dean Devlin and Roland Emmerich refused an on-screen credit.
Stargate SG-1 is the only television series currently endorsed and supported by the United States armed forces (particularly the Air Force).
The real Air Force Chief of Staff Michael E. Ryan appeared as himself in the episode Prodigy (4.19) just before his retirement.
While shooting the episode Prodigy (4.19), Richard Dean Anderson asked special guest star, Air Force Chief of Staff Michael E. Ryan, "Do you really have Air Force colonels who act the way I do?" General Ryan replied, "Yes, and worse!"
General Ryan's successor, General John P. Jumper, followed the example and will appear in the season 7 finale as himself. He was originally scheduled to appear in an episode filming in April, but the start of conflict in Iraq made him postpone his appearance.
Apophis was a real Egyptian god, despite many fans' difficulty in finding any information on him. "Apophis" is an obscure Greek name for Apep, the Egyptian god of darkness and night. The native names of Egyptian deities are not widely known except to Egyptologists because most Egyptian mythology was brought to the western world by the Greeks, who altered Egyptian words and names to conform to Greek phonology. For example, Bast the cat-god, was probably pronounced something like "Pasht".
The "Tollan Homeworld" shows were shot at Simon Fraser University.
The Oval Office set used for the show is the same one used in the motion picture X2 (2003).
The prop used to portray the device which controls the Tok'ra memory recall device which looks like a "wand" is actually an electric nose hair trimmer and is used unaltered
There are several references made by the character Jack O'Neill (Richard Dean Anderson) to The Simpsons. In the penultimate episode of Season 7, he goes so far as to tell another character: "The analogy is perfect: Burns as Goa'uld." Two other throw-away comments indicate his favorite show airs on Sundays (same day as The Simpsons); at one point, when he realizes it is a Sunday and forgot to set his VCR to tape The Simpsons, he uses Homer Simpson's signature "D'oh!" He also uses other Homerisms, as in episode 1.21, "Within the Serpent's Grasp", when he responds to a Goa'uld long-range visual communicator with "Mmmmmm...cool TV". Richard Dean Anderson is on record saying that The Simpsons is his favorite TV show.
Children of the Gods and the Showtime airings of this series have a line between the words "Stargate" and "SG-1" in the title/logo. The syndicated airings do not have this line.
The series has three different opening credits sequences. The first is the original non-clip version, which was used for the premiere and Showtime airings of the show. It was based on the Stargate movie opening credits, panning around a statue of Ra. The second opening credits sequence/set was the one used for syndicated airings. It includes clips from the series. The third opening credits sequence was used on Sci Fi Channel. It is similar to the first sequence through not showing clips, but pans in and out on an activating Stargate. It ends showing SG-1, from the back and in a row of four, entering the Stargate.
Peter DeLuise has directed a number of episodes, finding a way to appear in front of the camera each time (a la 'Alfred Hitchcock' ). He has played a gate guard, a technician, and even a younger, more handsome version of a character played by his father, Dom DeLuise.
Peter DeLuise tries to work the name "Penhall" into every script he directs. This was the last name of his character from "21 Jump Street" (1987). In the season 7 episode "Orpheus" Jack calls out to two soldiers; Hanson and Penhall. Hanson was the name of Johnny Depp's character.
The first season episode "There But For the Grace of God" is extremely similar to a 1970 "Doctor Who", episode, "Inferno," where a character visits an alternative, military-run Earth, which is about to be destroyed by an "alien" force.
During the first season finale, while the SG-1 team is on a Goul'd Mother ship, O'Neill asks Teal'c if the Goul'd "TV" gets Showtime. A reference to the Showtime network, on which the series airs.
In the episode "Seth", there is a scene where Dr. Daniel Jackson is explaining to the rest of SG-1 about the history he has learned about a Goa'uld named Setesh (aka the Egyptian god Set or Seth) on the internet. On the screen with Middle Ages information on Seth, the printed information actually contains information/history from the White Wolf role playing game "Vampire: The Masquerade" concerning a clan of vampires who also worship the Egyptian god Set. In the episode Within the Serpent's Grasp, the original Showtime airing and DVD have a line in which O'Neill tells Skaara/Klorel that something is "bullshit." This word was edited out for syndication.
Originally intended to be one episode, "Jolinar's Memories" was so expensive that the production staff decided the only way to pay for it would be to split it up over two episodes by developing a second part. The second episode, "The Devil You Know", was written. Up to that point, it was almost as expensive for the two-parter as it was for the pilot, "Children of the Gods".
In the episode "Window Of Opportunity", Jack O'Neill can be seen reading a Latin for Novices book, and the author of the book is Joseph Malozzi, the writer of the episode.
While filming "The Curse," 'Anna Louise Plowman' (Sarah/Osiris) accidentally caused Michael Shanks (Dr. Daniel Jackson) to pass out while she was strangling him.
In the fourth season episode '2010', an allied alien race called the Aschen are seen developing a program to ignite Jupiter into becoming a star in order to use its moons as planets to be colonized, a homage to the movie and book '2010' (1984) which featured a similar climax.
In the season 5 Episode "Threshold" General Hammond and Col. O'Neill stand in the observation room watching as Teal'c undergoes the Last Rite. You can see a reflection on the glass below them of the candles in the isolation room, the candles have been arranged into the shape of the initials PD - Peter DeLuise directed this episode.
The fourth episode of season six, Frozen, features a fourth variation of the opening credits. It shows the sequence from the previous three episodes, with the Stargate being activated, the chevrons locking into place and panning in and out on the Stargate. But part of the screen is now taken up with clips from various episodes.
In episode 6.8, "The Other Guys", John Billingsley appears as a nerdish scientist who is a trekkie. He talks about "worshipping at the Altar of Roddenberry", and at one point when it appears he will die he says "I might as well be wearing a red shirt" (a reference to the original Star Trek series). Billingsley plays Dr. Phlox in "Enterprise" (2001). A further visual cue is a Klingon bat'leth (sword of honor) on the back wall of Khonsu's ('Adam Harrington' ) throne room.
In the Seventh series episode "Chimera" when Carter gets in the lift with O'Neill, the tune she hums, prompting O'Neill to ask who the guy is, is the Stargate theme.
The final two episodes of the show's seventh season were adapted from the script for the feature film Stargate 2.
The character 'Jack O'Neill' was ranked #10 in TV Guide's list of the "25 Greatest Sci-Fi Legends" (1 August 2004 issue).
