Blanchett was born in Ivanhoe, a suburb of Melbourne, Australia, the daughter of June, an Australian property developer and teacher, and Robert "Bob" Blanchett, a Texas-born United States Navy Petty Officer who met Blanchett's mother while stationed in Melbourne and who later worked as an advertising executive. When Blanchett was 10, she lost her father to a heart attack. She has described herself during childhood as "part extrovert, part wallflower". She has two siblings; her older brother, Bob, is a computer systems engineer, and her younger sister, Genevieve, worked as a theatrical designer and received her Bachelor of Design in Architecture in April 2008.

Blanchett attended primary school in Melbourne at Ivanhoe Girls Grammar School before completing secondary education at Methodist Ladies' College, where she explored her passion for acting. She studied Economics and Fine Arts at the University of Melbourne before leaving Australia to travel overseas. When she was 18, Blan