Mara's career started early, after she watched a musical in New York. She was bitten by the acting bug, and her mom sought an agent for the then 14-year-old Mara. After loosing out on a part for Homicide: Life on the Streets, Mara found limited success on shows like Law and Order and Everwood. She also appeared in four episodes of Nip/Tuck (Kelly Carlson) in 2003. A few years, and guest appearances on various TV shows later, Carlson landed a small, but pivotal role in Ang Lee's Brokeback Mountain, playing Heath Ledger's grown daughter Alma Jr. This helped her get a recurring role on 24, playing one the hottest computer analysts ever.

She has since been seen in We Are Marshall (2006) and the Mark Wahlberg thriller Shooter (2007). She will next be seen in movie The Open Road (2008). She also starred in the movie Zoom alongside Tim Allen.

For sports fans, it's interesting to know that Mara's great-grandfather on her father's side founded the N.Y. Giants, and her family still owns the team to this day. Growing up, she would frequently sing the national anthem before home games. Her great-grandfather on her mother's side, founded the Pittsburg Steelers. So who does Mara cheer for? "I can't answer that," she said.

• Flying Lessons (2009) (pre-production) (rumored) .... Sophie Conway
• The Open Road (2008) (post-production) .... Lucy
• Stone of Destiny (2008) .... Kay Matheson
• Transsiberian (2008) .... Abby
• Shooter (2007/I) .... Sarah Fenn
• Full of It (2007) .... Annie Dray
  ... aka 14 anni vergine (Italy)
  ... aka Big Liar on Campus (USA: TV title)
• We Are Marshall (2006) .... Annie Cantrell
• Fireflies (2006/I) .... Taylor
• Zoom (2006) .... Summer Jones / Wonder
  ... aka Zoom: Academy for Superheroes (USA: DVD title)
• "24" .... Shari Rothenberg (5 episodes, 2006)
       - Day 5: 1:00 a.m.-2:00 a.m. (2006) TV episode .... Shari Rothenberg
       - Day 5: 12:00 a.m.-1:00 a.m. (2006) TV episode .... Shari Rothenberg
       - Day 5: 11:00 p.m.-12:00 a.m. (2006) TV episode .... Shari Rothenberg
       - Day 5: 10:00 p.m.-11:00 p.m. (2006) TV episode .... Shari Rothenberg
       - Day 5: 9:00 p.m.-10:00 p.m. (2006) TV episode .... Shari Rothenberg
• The Californians (2005) .... Zoe Tripp
• Brokeback Mountain (2005) .... Alma Jr., Age 19
• Urban Legends: Bloody Mary (2005) (V) .... Samantha Owens
  ... aka Urban Legends 3: Bloody Mary (USA)
• "Jack & Bobby" .... Katie (6 episodes, 2005)
       - Under the Influence (2005) TV episode .... Katie
       - Friends with Benefits (2005) TV episode .... Katie
       - Querida Grace (2005) TV episode .... Katie
       - Time Out of Life (2005) TV episode .... Katie
       - Into the Woods (2005) TV episode .... Katie
        (1 more)
• "CSI: Crime Scene Investigation" .... Janelle Macklin (1 episode, 2004)
  ... aka CSI: Las Vegas (South Africa: English title: informal alternative title) (USA: syndication title)
  ... aka C.S.I. (USA: short title)
  ... aka CSI: Weekends (USA: promotional title)
  ... aka Experts, Les (Canada: French title)
       - Formalities (2004) TV episode .... Janelle Macklin
• "CSI: Miami" .... Stephanie Brooks (1 episode, 2004)
       - Murder in a Flash (2004) TV episode .... Stephanie Brooks
• Time Well Spent (2004) .... Girl
• Prodigy (2004) (TV)
• Peoples (2004) .... Jessica Anderson
• "Boston Public" .... Helena Gelbke (1 episode, 2003)
       - Chapter Seventy-Five (2003) TV episode .... Helena Gelbke
• "Cold Case" .... Jill Shelby (1 episode, 2003)
       - Look Again (2003) TV episode .... Jill Shelby
• "Nip/Tuck" .... Vanessa Bartholomew (4 episodes, 2003)
       - Cliff Mantegna (2003) TV episode .... Vanessa Bartholomew
       - Megan O'Hara (2003) TV episode .... Vanessa Bartholomew
       - Nanette Babcock (2003) TV episode .... Vanessa Bartholomew
       - Mandi/Randi (2003) TV episode .... Vanessa Bartholomew