Jeff St. John was born on 22 April 1946 in Newtown, Sydney, New South Wales, Australia. He died on 6 March 2018 in Perth, Western Australia, Australia.
Born with spina bifida, St John had been performing since childhood and made his first appearance on radio at the age of 8. By the age of 15 he could be seen on a TV talent show and in the mid-60s joined Sydney group The Syndicate.