Jonathan J. O'Neill

Jonathan J. O'Neill, also known as John or, most commonly, Jack, was a Human male who is a Lieutenant General, in the Starfleet Marine Corps, who served twenty years in the Stargate Program until he was transferred to the Homeworld Command building to become the head of Homeworld Command (also called Homeworld Security). He was the original leader of SG-1 and later became the commander of Stargate Command. In 2385 General O'Neill became the leader of SG-1 again.

SG-1
In 2360 Jack joined the Stargate Program and was given command of SG-1, the flagship team of the SGC. In 2381, he along with SG-1, Typhuss James Kira, and Colonel Samantha Carter finally tracked down the last Ba'al clone and sent him to the Tok'ra homeworld, where they witnessed the Extraction Ceremony, the :Tok'ra felt it only right that all of the current and former members of SG-1 attend the ceremony (O'Neill was a former member of the team who joined the current members, Mitchell, Typhuss, Samantha, Daniel, and Vala). It took a little over three hours for the Tok'ra to chant all of the charges against Ba'al, the last of the Goa'uld System Lords. All during this time, Ba'al was placed in a stasis chamber out of respect to the host. After all of the charges against Ba'al were presented, Ba'al was released from stasis so that he could face his executioners and give his final words. This Ba'al revealed that he might have been the last clone, but he wasn't the last Ba'al. The original still lived and wasn't traceable through a subcutaneous transmitter like the clones had been. The clone was aware of Ba'al's plan to go back in time and change the timeline in his favor by preventing the Stargate program from ever being created. The clone Ba'al bragged about Ba'al's plan, but didn't provide any details, but only that they had made a mistake in thinking that he was the last Ba'al. This was a rather unpleasant experience for Vala, who had been an unwilling host to Qetesh until the Tok'ra freed her, but she attended for the host's sake so that she could be there to offer emotional support once he was freed of the symbiote. The rest of the team returned to Earth so that they could go out to lunch with O'Neill, who promised to take them out to eat. While changing in civilian attire in the locker room, Daniel voiced the concern to Typhuss and Mitchell that the Ba'al clone might have actually been telling the truth and that they hadn't captured all of the Ba'als as they thought. What Daniel and the others didn't know was that a time traveling version of Cameron Mitchell had been aware of Ba'al's plan and gone back in time to prevent it. That version of Mitchell killed Ba'al and his Jaffa as they went back in time. Because of this act, the last of the Goa'uld System Lords had actually been killed long before SG-1 was even aware of the Goa'uld's existence.

Sara O'Neill
At some point, he married Sara O'Neill and together they had a son and named him Charlie O'Neill. Shortly before his first mission Charlie, was killed while playing with his phaser and, in the aftermath of this tragedy, he separated from Sara O'Neill.

Kerry Johnson
He had a relationship with SCIS Agent Kerry Johnson, but she felt there was something deeper between him and Lt. Colonel Samantha Carter. Kerry told him to retire but he didn't take her advice. She goes on saying they were making big error if they let rules stop their feelings.

Samantha Carter
He has feelings for Colonel Samantha Carter that seem to be reciprocal; they were once both forced to admit it to avoid being labeled as Za'tarcs. He has never pursued a relationship with her, keeping well within the rank border. He even encouraged her during her engagement to Pete Shanahan. When he and Typhuss were stuck in the effects of the Time loop machine and had the opportunity to do whatever they wanted with no fear of the consequences, one of the things he did was to give his resignation to Major General George S. Hammond. When Carter asked him why, he replied, "So I can do this." Then he pulls her into a long kiss, which she evidently reciprocated. Jacob Carter has hinted at knowing their feelings, as have Typhuss and Major General George S. Hammond.

Typhuss James Halliwell
When Typhuss once stated he was a brother to him, though it had no importance as he was trying to comfort him while Major Samantha Carter was missing. Jack and Typhuss have a great respect for one another, despite their ranks. After Typhuss returned to Earth in late 2377 they have been on a first name basis, even after Jack was promoted.

Daniel Jackson
Jack and Daniel have a great respect for one another, despite their differences. Ever since the mission to Abydos, they have been on a first name basis, even after Jack was promoted. Although their relationship became more strained after Jack lied to Daniel during his undercover operation and ignored Daniel's advice during a crucial mission, in the aftermath of Daniel's Ascension they became closer once more, Daniel commenting that he was essentially Jack's best friend when talking with an alternate version of Jack.

Personality and traits
Jack has a very dry sense of humor and is impatient with complicated explanations. However, in a conversation with Lt. Colonel Samantha Carter, he explains that he is worried about her because she has not tried to baffle him with scientific babble for a few days. When he is asked a scientific question he doesn't know the answer to, he often jokingly answers with "magnets," or some variation of the term. As stated by Cassandra Fraiser, Jack pretends he's not as smart as he really is.

Jack has a tendency to not lock his house when leaving, which has caused some unwanted visits. Jack O'Neill also naturally possesses the Ancient Technology Activation gene. His service number is 69-4-141. O'Neill loves cake, often referencing it when formal situations or events arise with the phrase "I hope there's cake". He goes out of his way on several occasions to make sure cake is being served to celebrate a particular event. His favorite color is peridot. If he could have dinner with one person in the world it would be Mary Steenburgen. His favorite television show is the The Simpsons. In his free time, Jack enjoys fishing in the lake next to his cabin in Minnesota. After several failed attempts to get Carter to come with him, he finally succeeded shortly after the fall of the Goa'uld Empire. He also enjoys Boxing, Chess, Golf and Ping pong.

The Asgard showed great fondness toward him. Loki even stated that: "O'Neill is legendary" hinting at the Asgard's view of him. To them, he led his people through the galaxy and proved to them that the Federation were well on their way to be the "Fifth Race". He also downloaded, twice, the knowledge of Ancients and through this created the Replicator disruptor which saved their planet. When Earth was accused of stealing over Asgard, Nox and the Tollan's technology, the Asgard chose him alone to prove his people weren't the culprits.