Joe Camilleri was born in Malta in 1948. The family migrated to Australia when he was two. Camilleri grew up in Port Melbourne and listened to rock music on the radio. His mother called him Zep and he became known as Jo Zep. Camilleri began his music career in 1964 when literally thrown onstage to sing with The Drollies. He played blues and R&B in the mid-1960s with The King Bees and was then a member of Adderley Smith Blues Band.
In 1968, lead singer for the band, Broderick Smith had been conscripted for National Service during the Vietnam War. Camilleri lasted a year with Adderley Smith, and enjoyed working with the band including guitarist Kerryn Tolhurst (later in The Dingoes with Smith). According to Australian music journalist Ed Nimmervoll, Camilleri was sacked for sounding too much like Mick Jagger and upstaging other band members. After Adderley Smith, Camilleri was a member of various bands, including The Pelaco Brothers during 1974–1975.