Dr Gannon is a Consultant Obstetrician & Gynaecologist with 18 years’ experience as a specialist, having delivered over 5,000 babies.

Dr Gannon is Chair of St John of God Health Care’s National Obstetric & Midwifery Specialty Committee which oversees the group’s maternity services across three states.

Between 2012 and 2023 Dr Gannon was Head of Department of Obstetrics and Gynaecology at St John of God Subiaco Hospital. In 2022 he was appointed Chair of the hospital's Medical Advisory Committee.

Dr Gannon is Chair of the state Perinatal and Infant Mortality Committee. He is President of MDA National, WA’s largest medical indemnity provider.

Dr Gannon served as National President of the Australian Medical Association (AMA) from 2016 to 2018. Prior to that he was President of AMA WA and chaired the AMA Ethics and Medicolegal Committee.

He was born at St John of God Subiaco Hospital. He grew up in Perth and graduated from the University of Western Australia, before training at Royal Perth Hospital and King Edward Memorial Hospital.

Dr Gannon had Fellowship training in high risk obstetrics, maternal medicine and urogynaecology at the Rotunda Hospital in Dublin and St Mary's Hospital in London.