In 1999, Portman enrolled at Harvard University to study psychology, alongside her work as an actress; she completed a bachelor's degree in 2003.
Her first role was in the 1994 action thriller Léon: The Professional, opposite Jean Reno.
She played leading roles in the historical dramas Goya's Ghosts 2006 and The Other Boleyn Girl 2008 , and also appeared in Thor 2011 and its 2013 sequel.