She made her screen debut in the television adaptation of Danielle Steel's romance novel Zoya in 1995.
She had guest television appearances and supporting film roles, as well as a featured role on the teen drama television series Time of Your Life (1999–2000) and a supporting role in the war drama Pearl Harbor (2001).
For her work on the series, she won the Golden Globe for Best Actress – Television Series Drama and the Screen Actors Guild Award for Best Actress in a Television Drama,
She received additional praise for her performance in the romantic comedy 13 Going on 30 (2004), and went on to portray Elektra in the superhero films Daredevil (2003) and Elektra (2005).
She continued to achieve commercial success with performances in the comedy-drama Juno (2007), the romantic comedy Ghosts of Girlfriends Past (2009) and the romantic comedy Valentine's Day (2010).