Chloe O'Brian is a fictional character from the television series 24, which aired from 2001 to 2010. She is portrayed by actress Mary Lynn Rajskub and serves as a computer analyst for the Counter Terrorist Unit (CTU). Chloe is known for her technical skills, quick thinking, and often sarcastic demeanor, making her a key asset in the fight against terrorism. Throughout the series, Chloe develops a close working relationship with the show's protagonist, Jack Bauer, played by Kiefer Sutherland. Her character evolves from a supporting role to a more prominent figure, showcasing her loyalty and determination in high-pressure situations. Chloe's contributions are vital to the success of various missions throughout the series.