Tom O'Neill was a general surgeon at Sir Patrick Dun's Hospital in Dublin, Ireland. He was born on 22 May 1912 near Newmarket, County Cork, and attended Presentation College, Cork, and then University College, Cork, where he studied medicine. He qualified in 1935. After house posts, he went to England. He trained at Halifax Royal Infirmary and was a surgeon in the Emergency Medical Service in London in the Second World War, working through the Blitz. He was then a resident surgical officer and surgical chief assistant at Manchester Royal Infirmary. In 1949 he became a consultant surgeon at Sir Patrick Dun's Hospital in Dublin. At the time, his appointment caused controversy: it was then unheard of for a Catholic surgeon to be appointed to a Protestant hospital. He stayed at the hospital until his retirement in 1977. He was also a lecturer at Trinity College, Dublin. He wrote mainly on partial gastrectomy for peptic ulcer, for which he invented a useful modification. He was president of the Royal Academy of Medicine in Ireland from 1988 to 1990. He was also retained by leading insurers as a medical expert. Outside medicine, he played hurling as a student, and then golf later on. In 1945 he married Dorothy Moriarty, who was also a doctor. They had five sons. Tom O'Neill died in 2000.