Charlie O'Neill

Charlie O'Neill was the only son of Jack and Sara O'Neill. He died, shortly before the first mission to Abydos, when he accidently shot himself with his father's personal gun. 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 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. (SG1: "Cold Lazarus")

Two years later, when torturing O'Neill for information on Ne'tu, Apophis used the memory of Charlie's death. (SG1: "The Devil You Know")

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.