Kate Mara was born on February 27, 1983. She is an American television and film actress. Beginning acting in her hometown of Bedford, New York, she moved from the stage to her first film, Random Hearts (1999). Her notable roles include appearances in the Academy Award-winning film Brokeback Mountain, playing the daughter of Heath Ledger's character, and on the Fox television series 24, as computer analyst Shari Rothenberg. She has since appeared in the feature films We Are Marshall (2006), Shooter (2007), Transsiberian (2008), Stone of Destiny (2008), and The Open Road (2009). Mara joined the cast of the HBO series Entourage for its sixth and seventh seasons. Mara had a cameo appearance in Iron Man 2, and her upcoming films in 2010 include happythankyoumoreplease, Ironclad, and 127 Hours.

kate was born and raised in Bedford, New York, the daughter of Timothy Christopher Mara, a scout for the New York Giants, and Kathleen McNulty (nee Rooney). She is Irish-Italian-American; her family name used to be O'Mara. Mara has one older brother, Daniel, and two younger siblings, Patricia and Conor. Mara wanted to be an actress since seeing Les Miserables at a young age; she said she "fell in love with Broadway and musicals", and grew up watching movie musicals on television and going to Broadway shows with her mother. She was especially a fan of Judy Garland's films. She began acting at the age of nine in a school musical, and attended several youth theater-arts schools, and appeared in community theater and in school plays. Mara described herself to Esquire magazine as "painfully shy" while growing up, and said Mara only had one friend.

Beginning at a young age, Kate continually asked her mother to help her get an agent. Her mother got the name and address of a management company, sent in a photograph, and Kate signed with her first agent, beginning her professional career at the age of 14. Mara's first audition was for the television drama Homicide: Life on the Street. She didn't get the role, but knew from then on that she just wanted to act. Mara was accepted into the Tisch School of the Arts at New York University to study musical theater and graduated from Fox Lane High School a year early. Kate felt pressure from her parents to go to college, but was already getting work as an actress, so she deferred for three or four years before deciding not to go. Mara moved to Manhattan in order to act full time.