She garnered widespread recognition after appearing in the mainstream teen drama Varsity Blues (1999), as well as for a recurring role as Ruby on the television series Felicity (1999–2001).

Smart co-starred with Ryan Reynolds and Anna Faris in Just Friends (2005), followed by the sports drama Peaceful Warrior (2006).

[5] Her mother, Judy Lysle (née Carrington), worked at a museum, and her father, John Boden Smart, was a salesman.

In 1996, she appeared in a small role as Queenie in the adaptation of John Updike's short story, directed by Bruce Schwartz, "A&P", later shown on Spike TV.

In 1999, Smart played the girlfriend of a popular American football player in the film Varsity Blues, reuniting her with Larter.

She costarred in the films Road Trip (2000), Rat Race (2001),[13] Starsky & Hutch (2004),[14] and the science fiction drama The Butterfly Effect (2004).

Smart appeared as Joy in the 2006 sports drama Peaceful Warrior, about a gymnast whose life changes after an encounter with a spiritual guide.

[18] She starred as Melissa in the 2008 independent horror film Seventh Moon,[19] and had a supporting role in Alexandre Aja's supernatural thriller Mirrors (2008).

On September 20, 2011, Smart married TV carpenter Carter Oosterhouse from the U.S. cable channel HGTV, in Traverse City, Michigan.