Chloe O'Brian

Chloe O'Brian is a fictional character played by actress Mary Lynn Rajskub on the US television series 24. An analyst at CTU Los Angeles (and later New York), she is Jack Bauer's most trusted colleague, often doing unconventional and unauthorized favors for him, even at personal risk to herself. As O'Brian, Rajskub appeared in 125 episodes of 24, more than any other actor except series star Kiefer Sutherland, who appeared in all 192 episodes of the series. UGO.com named her one of the best TV nerds. AOL named her one of the 100 Most Memorable Female TV Characters.