McArdle, John Stephen (1859–1928), surgeon, was born in September 1859 in Dundalk, Co. Louth, the second child of the six sons and two daughters of Robert McArdle, solicitor, and his wife, Margaret (née Callan), of Francis Street, Dundalk. He was educated in the Christian Brothers and St Mary's College, Dundalk, and the Catholic University's school of medicine in Cecilia Street, Dublin. While at university he played lacrosse at an international level, and he retained a keen interest in sport (particularly horse-racing) throughout his life. He graduated in 1877 and began work in Dublin at St Vincent's Hospital, where he was appointed a house surgeon on qualifying as a licentiate of the RCSI (1879); he subsequently became a licentiate of the RCPI and LM (1880) and a fellow of the RCSI (1884). He remained in St Vincent's, where he became a full surgeon in 1883.
McArdle specialised in the treatment of fractures and anatomical surgery, and was credited with introducing innovative surgical techniques to Dublin. During a trip to America in 1889 he visited Chicago to study the methods of the pioneering surgeon John Benjamin Murphy; later he became adept in the use of ‘Murphy's Button’, a mechanical device used for intestinal anastomosis. His professional energies were immense, however, and widely spread. Much of his time was spent in clinical teaching: he was elected professor of surgery in the Catholic University (1904), and received the degree of M.Ch. from the RUI (1905). McArdle was an original fellow of the Royal Academy of Medicine in Ireland, and president of the Irish Medical Association (1906–8). He held several other surgical positions, including surgeon to St Patrick's College, Maynooth, and consulting surgeon to the Children's Hospital, Dublin (1899–1928). He also operated in nursing homes throughout the city. A well-known and colourful Dublin character, he was popularly known as ‘the poor man's surgeon’ for his work among the poor. After a long illness he died 14 April 1928 at his home, 72 Merrion Square, Dublin.
McArdle's first marriage was to Madeline Forrest King (18 September 1882), with whom he had four children. In 1910 he married Eileen, daughter of John Michael Nugent, managing director of the Dolphin Hotel, Dublin; they had no children. A life-size portrait was held in UCD, but is now lost; another portrait is in the archives of the RCSI. A list of articles written by McArdle, and dealing mainly with abdominal surgery, can be found in Richard J. Hayes (ed.), Sources for the history of Irish civilization: articles in Irish periodicals, 9 vols (1970), iii, 384–5.