Dr. Jackson joined the SG-1 team on a voluntary basis to study the cultures of other planets. He holds a Ph.D. in Anthropology as well as a Ph.D. in Linguistics, and has prior experience with the culture of Abydos. He is an expert in ancient cultures and languages in addition to current ones; he speaks over 20 languages including ancient Egyptian. Originally he was contracted by the military to decipher a mysterious hieroglyphic cartouche. His subsequent translation of the cartouche allowed the Stargate to be opened for the first time.

He married Sha're, an off-world human and native of Abydos, after he chose to stay behind on the planet following the first mission, and he became something of a deity to the people of Abydos. His humanistic, liberal approach is often in conflict with the militaristic approach of the rest of his team. Some see him as a soft, brainy, clumsy scientist who carries a wide-eyed enthusiasm with him through every mission.