Aoki was born in New York City, New York, and grew up in California and London, attending high school at The American School in London. Her Japanese American father, Rocky Aoki, a former Olympic wrestler, was the founder and owner of the Benihana restaurant chain until his death on July 10, 2008. Her mother, Pamela Hilburger, is a jewelry designer of German and English heritage.
Aoki was discovered in New York at a Rancid concert she had gatecrashed. She started modeling when she was 13, the same year Aoki was introduced by her godmother to Kate Moss, who would later take the young Devon under her wing. She was signed onto Storm Model Management at age 14.
In 1998, at the age of 16, Devon replaced Naomi Campbell as the face of Versace. An A-grade student at school, Devon chose not to go on to college, believing that working and traveling offered her a "broader and deeper education" than a degree.