Rodney McKay's sister, Jeannie Miller, is played by Kate Hewlett, who is David Hewlett's sister in real life.
During the first season and much of the second, most of the Wraith males were played by the same actor: James Lafazanos.
Although David Nykl and Paul McGillion were born in the Czech Republic (then Czechoslovakia) and Scotland respectively, both moved to Canada when very young and speak with a Canadian accent. The accents used for their characters come from their respective parents.
By the end of season five, John Sheppard has given names to five wraith, which are as follows: Steve, Bob, Michael, Todd, and Kenny.
Each episode has a pop culture reference, usually Star Wars, Star Trek, or one of various sci-fi movies, to make the show appear grounded in the real universe.