Jonathan J. "Jack" O'Neill, Lieutenant General, USAF, is a fictional character in the military science fiction franchise
Stargate, and primarily one of the main characters of the television series
Stargate SG-1. He is most known as portrayed by actor Richard Dean Anderson, who played O'Neill in all the
Stargate media since 1997, when he took over the role from actor Kurt Russell, who portrayed the character in the
original Stargate film in 1994. O'Neill and Daniel Jackson are the only two characters to appear in both the original film and all 3 live-action
Stargate television series.