Casey was born on 24 December 1985, and spent most of childhood in Timaru, where she attended Gleniti School and Waimate Main School. She later moved to Wellington and attended Tawa College. From an early age, she was interested in radio and pop culture and music. She left school at the age of 15 and worked in Woolworths supermarket for 6 months. While working at Edgefest, she was inspired by the marketing manager to pursue a job in radio; she applied for radio school the next day and went on to study broadcasting at the NZ Radio Training School in Wellington.