Born in Winnipeg, Manitoba, Canada, and the child of two teachers, she moved to New Zealand when she was four. Her début performance, in the 1993 film The Piano, which was widely regarded as extraordinary even by critics who didn't like the film, saw her win an Academy Award for Best Supporting Actress; the second-youngest person to win an Oscar.

She completed her secondary education in Los Angeles, and took several well-regarded roles in various movies while doing so. She studied at Columbia University for one year, but has been on a leave of absence in order to continue her acting career. She returned to worldwide prominence with her role as Rogue in the blockbuster X-Men movie in 2000 and its sequel in 2003. She lives in New York.