Surgeon John Thomson (1847-1909), a Scot who made his life's work in Queensland, was a pioneer surgeon, radiologist and bacteriologist, and one of the founders of the St John Ambulance movement in Australia and the Railway Ambulance Corps. He was variously President of the British Medical Association (Queensland Branch), the Medical Board of Queensland, the Medico-Ethical Association, and the Intercolonial Medical Congress, which was held in Brisbane in 1899. A pioneer military surgeon in this country, he was the foundation Principal Medical Officer (as Surgeon-Major) of the Queensland Ambulance Corps within the Queensland Defence Force. His advocacy for a university north of Sydney was one of the factors which led to the foundation of the University of Queensland, a body which honoured him by the establishment of the John Thomson Lectureship, which for half a century was its most prestigious public oration. The life and times of this singular doctor exemplify one small class of pre-Federation medical pioneers whose professional outreach established a number of voluntary organisations which have blossomed in Australian society to the present day.