Cuthbert auditioned for the role of Mary Jane Watson in theSpider-Man film, but the role went to Kirsten Dunst.She began her Hollywood film career with small roles in Old School and Love Actually in 2003.
She appeared in the show's first three seasons, but not in its fourth; she guest-starred in only two episodes in the fifth season. She also reprised her role as Kim Bauer in 24: The Game and again guest-starred in five episodes of the seventh season and in two episodes of the eighth season.
Cuthbert landed her first role in a feature film in the family drama Dancing on the Moon (1997). She appeared in several other Canadian family-themed movies and an airplane thriller, Airspeed. Cuthbert starred in the Canadian television movieLucky Girl in 2001 and was awarded a Gemini Award for her performance.
Cuthbert also co-hosted Popular Mechanics for Kids, which was filmed in Montreal. Her reporting captured the attention of then–First Lady Hillary Clinton, who invited her to visit the White House.
She made her first televised appearance as an extra in the horror- themed series for children Are You Afraid of the Dark? she later became a series regular on the show.
Cuthbert was born in Calgary, Alberta, the daughter of Patricia, a homemaker, and Kevin, an automotive design engineer. She has two younger siblings, Jonathan and Lee-Ann, and she grew up in Greenfield Park, near Montreal, Quebec.
She has also had starring roles in the 2005 House of Wax film and the 2007 horror film Captivity. Her most prominent role is as Kim Bauer in the American action-thriller television series 24.