Cornish was born in Lochinvar, New South Wales, as the second of five children. She grew up on a 70 hectare farm,attended Catholic school, and was fascinated by independent and foreign films.
Her name is rather notorious for being linked to actor Ryan Phillipe during his highly publicized divorce from Reese Witherspoon, with whom he has two children. The four-year relationship between Phillipe and Cornish ended in 2010.
Career
Wildside, 1997—99, Outriders, 2001; (TV films) Close Contact, 1999, Marking Time, 2003; (films) The Monkey's Mask, 2000, Horseplay, 2003, One Perfect Day, 2004, Everything Goes, 2004, A Good Year, 2006, Stop-Loss, 2008, Bright Star, 2009, (voice) Legend of the Guardians: The Owls of Ga'Hoole, 2010