Oakes was born in Newcastle, New South Wales, the son of Wes and Hazel Oakes. His father worked for BHP as an accountant. When Oakes was six years old, his father was transferred to Cockatoo Island, a small island off the coast of Derby, Western Australia, where there was an iron ore mine. He began his schooling at a one-teacher school with only 20–30 children. Oakes later moved back to New South Wales and attended Lithgow High School. He graduated in 1964 from the University of Sydney while working part-time with the Sydney "Daily Mirror".