Jack O'Neill

Jack O'Neill
Richard Dean Anderson as Jack O'Neill in a promotional photo for Stargate SG-1.
First appearance	Stargate
Last appearance	"Incursion" (Universe)
Created by	Roland Emmerich and Dean Devlin
Portrayed by	Kurt Russell (1994) Richard Dean Anderson (1997-2010)
Information
Species	Human
Occupation	United States Air Force Colonel Brigadier General Major General Lieutenant General
Spouse(s)	Sara O'Neill (wife in film)/(ex-wife in television series)
Children	Tyler O'Neil (son, in film) Charlie O'Neill (son, deceased, in television series)

Jonathan J. "Jack" O'Neill, Colonel (later promoted), USAF, is a fictional character in 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 three Stargate television series.

In his first appearance in the 1994 film as Jack O'Neil, the character leads the first team to go through the Stargate on a reconnaissance mission. He subsequently becomes the main character of the television series Stargate SG-1 created in 1997 as a sequel to the movie. In the first seven seasons of the show, O'Neill is the leader of the team SG-1, a part of Stargate Program whose goal is to explore the galaxy and defend against alien threats.

The character became less prominent in the eighth season in which he is promoted Commanding Officer of Stargate Command, therefore greatly reducing the character's time spent exploring via the Stargate. Anderson chose to reduce his character's status to spend more time with his family, eventually leaving the show at the start of its ninth season and only appearing four times until the end of the series in its tenth and final season. The character's absence from the show was explained by his promotion to the position of head of the Department of Homeworld Security.