|Out of universe information|
Charlie O'Neill was the only son of Colonel Jack O'Neill and Sara O'Neill. He died, shortly before the first mission to Abydos, when he accidentally shot himself with his father's personal gun. Judging from his appearance, he was about eight years old at time of his death.
Jack O'Neill blamed himself for what had happened to his son and came close to committing suicide. However, his adventure on Abydos with Dr. Daniel Jackson brought him out of his depression and caused him to lighten up a little. (Stargate) Nevertheless, Sara divorced her husband shortly after his return from the first Stargate mission. (SG1: "Children of the Gods")
About a year later, an alien entity, impersonating O'Neill, tried to find Charlie so he could make him "better," but didn't realize how permanent physical death was to Humans. However, the being did impersonate Charlie as Jack took him back to his planet to give him a chance to say goodbye to his son. (SG1: "Cold Lazarus")
When dealing with Malakai, an alien archaeologist trying to make an Ancient time machine work so that he could go back and see his wife again after her death of a congenital heart condition, O'Neill used Charlie's death to show Malakai that he knew the other man's pain and convince him that the pain he would feel from reliving his wife's death wasn't worth the chance of seeing her again. (SG1: "Window of Opportunity")
After invading Jack's subconsciousness mind in 2002, the Human-form Replicator First made him relive Charlie's death. First told Jack that he was right to blame himself and that Charlie would still be alive if not for his carelessness. (SG1: "Unnatural Selection")
- In an alternate reality which Daniel Jackson visited in 1998, Charlie likewise accidentally shot himself with his father's personal gun in 1995. Shortly afterwards, Jack O'Neill was part of the original team to travel through the Stargate to Abydos with the intention of detonating a nuclear warhead. As a result of Charlie's death, he was willing to commit suicide on the Abydos Mission, as was his counterpart in our reality. (SG1: "There But for the Grace of God")
- In an alternate timeline created by Ba'al in which the Stargate Program never existed, Charlie was still alive in 2008 and lived at home with his father. (Stargate: Continuum)
- In another alternate timeline, Charlie had a half-sister Jade O'Neill, the daughter of Jack O'Neill and Samantha Carter. (SG1: "Relativity")
Behind the scenesEdit
In the film, the character's name, as it appeared on a certificate, was Tyler O'Neil. It's been speculated that "Tyler" may be his actual given name and that "Charlie" is only a nickname. In Bill McCay's Stargate novels, the character was named Jack O'Neil, Jr. after his father.