John graduated from RCSI in 1990 and went on to complete his specialist training in Emergency Medicine in the UK, Ireland, and Australia. After completing his Internship at Beaumont Hospital and a Masters degree in Physiology in UCD, he completed the Western Anaesthesia Scheme in Galway before completing his Emergency Medicine training. He worked in Emergency Medicine at Hope Hospital in Salford before completing the Higher Specialist Training scheme in Emergency Medicine at The Royal Infirmary of Edinburgh. He spent time working in the Liverpool Hospital in Sydney before returning to a Consultant post at University Hospital Galway in 2001. He has been the Clinical Lead in the ED since 2008.

John has a passion for prehospital medicine, and has been the Western Medical Advisor to the National Ambulance Service since 2004. John served as the Medical Lead and Team Doctor for Connacht Rugby for almost 20 years, and was a longstanding member of the Irish Rugby Football Union Medical Advisory Committee.

John is committed to Academic EM through teaching and as a member of the Academic Committee for the Irish Association of Emergency Medicine. He has taught ATLS for over 20 years. He was awarded Honorary Personal Professor in Emergency Medicine at the University of Galway in 2022.

As well as being a keen ornithologist, John also keeps 9 chickens at home and is a regular supplier of free range eggs to the department!