After beginning her career in small parts in a New York City theatre troupe, she has moved on to leading roles in plays by writers as diverse as William Shakespeare and David Mamet. Her film career has included both commercial and critical successes, ranging from teen romantic comedies such as 10 Things I HateAbout You (1999) to dark art house pictures such as The Business of Strangers (2001).
She is also known for playing the supporting character Nicky Parsons in the Bourne film series and the leading role in Save the Last Dance, and for her role in Mona Lisa Smile. In 2010, Stiles played Dexter Morgan's new love interest in the fifth season of the Showtime series Dexter.
Be on the lookout for Stiles to reprise her role as Nicky Parsons in the upcoming film Jason Bourne.