The third season of the military science fiction television series Stargate SG-1 commenced airing on Showtime in the United States on June 25, 1999, concluded on Sky1 in the United Kingdom on March 8,

The fourth season of Stargate SG-1, an American-Canadian television series, began airing on June 30, 2000 on Showtime. The fourth season concluded after 22 episodes on February 14, 2001 on British Sky