"Jack Bauer was born in Santa Monica, California, on February 18, 1966, to Phillip Bauer, who placed his livelihood in his company, BXJ Technologies. The name of Jack's mother is unknown. Jack had one brother, Graem Bauer. Phillip originally planned to give the company to Jack, but as Jack said in Day 6, "I just had to go my own way."

Jack has a Bachelor of Arts degree in English Literature from the University of California, Los Angeles and a Master of Science degree in Criminology and Law from the University of California, Berkeley. He enlisted in the U.S. Army and later graduated from Officer Candidate School. His MOS was infantry. He first served in the Green Berets, and was later a member of the 1st Special Forces Operational Detachment-Delta (1st SFOD-D), popularly known as Delta Force. Among his awards and decorations are the Silver Star, the Purple Heart, and the Legion of Merit. Apart from Special Forces training, he received Airborne, Air Assault, and Ranger training. He left the Army with the rank of Captain after fifteen years of service.

While in the U.S. Army, he married Teri Bauer and had one child, Kim Bauer. Following his military career, Jack worked for both the Los Angeles Police Department's Special Weapons and Tactics unit and for the Central Intelligence Agency as a case officer in the clandestine service. He was recruited into the Counter Terrorist Unit by Christopher Henderson.

He has demonstrated being at the peak of physical and mental condition. He has also shown a high proficiency with firearms (typically using a SIG P228 as his weapon of choice for a while, then switching to a USP Compact, until later he switches again, this time to a P30). He also can handle explosives and electronic devices, and has a high resistance to torture (after being kidnapped by Chinese agents and tortured for almost two years, it is revealed he didn't speak a single word the whole time). He is fluent in German and has demonstrated some ability to either speak or understand Spanish , Russian , Arabic , and Serbian. He is also shown to be capable of flying planes and helicopters. Jack is a formidable hand-to-hand combatant from his years in the United States Army. He appears to be a daring and seemingly indestructible agent.

Jack Bauer wants to have a normal life and to be happy, but his commitment to his country often brings him into conflict with that goal. He is required to serve a sometimes-hypocritical bureaucracy that acknowledges his service, but will not hesitate to hold him responsible for the more extreme actions that they themselves may directly or indirectly authorize.

Jack has lost his wife Teri, murdered by a traitor who had infiltrated CTU. His relationship with his daughter Kim is at times tumultuous while at other times accepting of who he is and what he must do. In his goal to find peace he gets involved with Audrey Raines, the daughter of Secretary of Defense Heller, whom Jack works for. The relation with the Secretary's daughter is all but severed when Jack makes the decision to save a material witness over Audrey's ex-husband. He lost his best friend Tony Almeida and former boss Michelle to a car bomb. He lost his friend, former President Palmer, to the same assassin who killed his friend. His girlfriend Renee Walker was killed by an assassin's bullet. His own government that he has sworn to protect has turned on him (former President Logan, President Taylor), and at the beginning of may he is on trial for his interrogation tactics. Finally, the friend he thought was dead (Tony Almeida) betrays him when he turns to terrorism only to seek revenge for the person who killed his wife, Michelle."