Sarah Clarke was born in St. Louis, Missouri. She attended Indiana University, where she studied Fine Arts and Italian. She spent a year studying abroad in Italy, where she first began acting.
Upon returning to the U.S. she began studying architectural photography. She received free acting lessons in return for taking photographs of a cultural arts center, and she studied acting at Circle in the Square, Axis Theater Company, and The Willow Cabin Theatre Company. In 2000 she was cast in the independent film Pas de deux, for which she won an award.
She has also had television roles in shows such as Ed, Sex and the City, and House.
She is probably best known for her role in the hit television show 24. She played the character, Nina Meyers, who played a big part in the shows first three seasons.