Glenn Barrie Shorrock was born on 30 June 1944 in Chatham, Kent, England. His family migrated to Adelaide, South Australia, on the "Orcades" in August 1954 when he was 10. His father, Harry Shorrock, was a Yorkshire-born fitter and turner at the Weapons Research Establishment in Salisbury, South Australia. The 1954–55 summer had days of and Black Sunday bushfires ravaged the Adelaide Hills in January 1955. His London-born mother, Joyce Shorrock, was not impressed with Australia and she took Shorrock and his younger sister back to UK on the "Strathmore", only to return to Australia on the "Fairsea" for a second attempt in 1956. The family settled in Elizabeth, north of Adelaide.