Born in 1994, in the small town of Lochinvar, New South Wales, Australia, Isabelle Cornish surprisingly was able to follow family ties to Hollywood. Her sister, Abbie Cornish, 12 years her senior, appeared in a number of films in Australia and Hollywood, including "Bright Star" (2009) and "Sucker Punch" (2011). The younger Cornish began her own screen career in guest roles on Australian television shows such as "Rescue: Special Ops" (Nine Network, 2009-2011) and "Dance Academy" (ABC1/ABC3, 2010-13).
Her first recurring role came on the long-running soap opera "Home and Away" (Seven Network, 1988-). She was a series regular on "Puberty Blues" (Network Ten, 2012-14), a coming-of-age story set in a 1970s Australian surf town. The show played for two seasons. Cornish made her U.S. screen debut as a series regular on the Marvel series "Inhumans" (ABC, 2017-) as Crystal, who has the ability to control the elements.