Rooney Mara was born Patricia Rooney Mara on April 17, 1985 in Bedford, NY. She is part of an NFL family, with her father Timothy Christopher Mara being an executive of the New York Giants. Her grandfather, Wellington Mara was the long-time owner of the team, and the ownership then went to her uncle John Mara. Her great-grandfather, Tim Mara, was the founder of the Giants, and her other great-grandfather Art Rooney, Sr. was the founder of the Pittsburgh Steelers.
She was inspired to act after watching musical theatre and classic movies with her mother. She also admired her sister, Kate Mara, and wanted to be an actress like her. However she resisted and held herself back from it because she didn't see it as a serious career choice, but more importantly, she was scared of failure. As a result, she only appeared in one play while in high school: Romeo and Juliet. She gained confidence while she was at New York University and took on parts in student films.
She landed a bit part in Urban Legends: Bloody Mary (2005), which her sister appeared in as well. She went on to make her professional debut in a 2006 episode of Law & Order: Special Victims Unit as Jessica DeLay, a girl who bullies overweight children. The following year, she guest starred on an episode of the series, Women's Murder Club. In 2008, she appeared on an episode of The Cleaner as well a role in the feature film, Dream Boy.
In 2007, Mara got her big break, landing a role in the film, Tanner Hall, which was released in 2009. Originally auditioning for the role of a supporting role, she ended up landing the lead. Tatiana von Furstenberg, the director of the indie film, was so impressed by Mara's audition that she asked her to come back and try out for the lead. "My favorite thing about acting isn't necessarily the acting part. It's that you never stop learning, you're constantly learning new skills and new things about people. To me that's really interesting and fun."
Tanner Hall debuted at the 2009 Toronto International Film Festival, and shortly after, Mara earned a "Rising Star" award at the 2009 Hamptons Film Festival and a "Stargazer Award" at the 2010 Gen Art Film Festival. Also in 2010, Mara landed her first lead role in a major feature, the remake of A Nightmare on Elm Street. She kept up the momentum that year with the role of Erica Albright in The Social Network.
Mara's claim to fame came when she was cast as Lisbeth Salander in The Girl With the Dragon Tattoo, an adaptation of the first Millennium book trilogy by Steig Larson. After an intense auditioning process, she landed the part and went to great lengths to prepare for the part. Her hair was cut short and dyed black, she added many piercings all over her body, she took on a temporary dragon tattoo, and learned how to skateboard and kickbox, as well as going through dialect and computer training. "There aren't many interesting and diverse parts out there for women. There seem to be a few different stereotypical roles that get recycled, so it was refreshing to have this complex character for a woman; very rare."
Mara's performance was a hit with critics, earning her universal praise and a nomination for the Golden Globe Award for Best Performance by an Actress in a Motion Picture " Drama and another nomination for an Academy Award for Best Actress.
Mara founded the charity Faces of Kibera, with the goal of providing housing, food, and medical care for orphans in Kibera, a slum in Nairobi, Kenya. The charity auctioned Steelers and Giants memorabilia in order to raise money in order to purchase land for the orphanage. In 2009, she stated that the charity was started out of frustration with the fact that so many nonprofits are merely business opportunities; "The people who need help aren't really getting it. So I started my own." As her acting career began to take off though, she found it harder to find a balance. In 2011, the charity merged with Uweza Foundation, which run focuses on empowering members of the Kibera community through various programs. Mara is still involved with the program, serving as the president of the board of directors.