Charlie, Jack O'Neill's only child, died at a young age just before the first Abydos mission. Charlie had been a happy child who loved playing baseball with his father. O'Neill had never allowed his son to play with guns, but two weeks after a disagreement about a water pistol, young Charlie accidentally shot and killed himself with his father's handgun. O'Neill never forgave himself. He and his wife became estranged, and he retired from the military, only to return later to join the SGC. It was following the mission to P3X-562, when SG-1 encountered crystals that could emulate other life forms, that O'Neill was able to confront the pain of losing his son and begin to heal.

Portrayed by: Kyle Graham, Dillon Moen

Cross Reference: Jack O'Neill, Sara O'Neill

Episode Reference: Cold Lazarus, The Devil You Know