Irwin, Sir Samuel Thompson (1877–1961), surgeon, rugby player, and politician, was born 3 July 1877 in Limavady, Co. Londonderry, son of John Irwin of Limavady. He was educated at Foyle College, Derry, and QCB, where he graduated BA (1900) and MB (1902). His university career was outstanding; as well as being president of the students’ council, he was a member of the QCB rugby football club, which won Ulster senior cup medals in 1900 and 1903. For three years (1900–03) he was an international rugby forward and was capped nine times for Ireland, before retiring definitively. He was later president of the IRFU (1935–6).
After two years (1902–4) as house surgeon in the Royal Victoria hospital, Belfast, Irwin went to St Peter's hospital, London in 1904. On receiving his M.Ch. (1906) he proceeded to Edinburgh, qualifying FRCS in 1909. From 1912 to 1930 he was surgeon in the Ulster Hospital for Children and Women, but served in the RAMC during the first world war, receiving the rank of captain. In 1918 he was appointed visiting surgeon, and five years later, attending surgeon at the Royal Victoria hospital, Belfast, in which institution he remained until his retirement in 1945. His particular area was orthopaedics and the surgery of the peptic ulcer. He was vice-president of the British orthopaedic association and president of the Northern Irish branch of the British medical association. His retirement was delayed from 1942 to 1945 because of the second world war, in which he served as consultant surgeon to the British troops stationed in Northern Ireland. For this he received the CBE in 1947. Ten years later he was knighted.
A senator of QUB in 1931, he was elected Unionist member of Stormont for the QUB seat (1948–61) at a by-election in April 1948. ‘As unswerving in his unionism as in his presbyterianism’ (Times, 22 June 1961), he was aged 71 when he entered Stormont, and proved popular with all parties. He spoke punctually and almost exclusively on medical matters, and was known as the ‘Doctors’ MP’. His interventions were precise and gracefully phrased. Though quiet and intellectual, he was known for his lavish and enjoyable parties. He died 21 June 1961 in Belfast. He married (1911) Mary Jemima, daughter of Abraham Sinclair, JP, of Newry, Co. Down; they had three sons and two daughters. His sons were all doctors and officers in the RAMC during the second world war.
The career of his eldest son, John Walker Sinclair Irwin (1913–2004), almost exactly mirrored his own. After graduating MB from Queen's in 1937, John was capped five times in rugby for Ireland (1938–9) and was afterwards president of the Ulster branch of the IRFU and later (1969–70) of the union itself. Volunteering for the RAMC in October 1939, he was captured at Dunkirk, when he stayed behind to nurse the wounded. After qualifying FRCS in Edinburgh (1947), he joined, three years later, the staff of the Royal Victoria hospital, Belfast, where his particular area was vascular surgery. He retired in 1978 and died in Belfast on 13 August 2004, survived by his wife, Betty, and five children.