Unusual for a series, Showtime ordered forty-four episodes (a second season) before showing the pilot. Halfway through the first season, they ordered another forty-four episodes.
The character "Jack O'Neill" was ranked number ten in TV Guide's list of the "25 Greatest Sci-Fi Legends" (August 1, 2004 issue).
Stargate SG-1 and its spin-offs are the only television series endorsed and supported by the United States Armed Forces, particularly the Air Force Space Command (the predecessor to the modern-day U.S. Space Force).
Christopher Judge (Teal'c) and Amanda Tapping (Samantha Carter) are the only cast members to stay with the series throughout its entire run and, consequently, to appear in 200 or more episodes.
The Asgard were voiced by creative staff, cast, and crew of the show. Thor was voiced by Michael Shanks, Heimdall was voiced by Teryl Rothery, and Loki and Kvasir were voiced by Peter DeLuise.
Martin Wood: multiple cameos throughout the series, most of which were uncredited, non-speaking roles. Several of them involved him and Dan Shea (Siler) standing in the background holding a large over-sized adjustable wrench.
Peter DeLuise: multiple cameos throughout the series, usually uncredited roles as background characters.