Born at Pewsey Vale, South Australia, the pastoral estate settled in 1838 by his grandfather Joseph Gilbert who came from Pewsey, Wiltshire, and thus a third generation Australian in one of the longest established South Australian families, he was educated at St Peter's College, Adelaide, and the University of Melbourne. He was a junior school-fellow of Sir Henry Newland FRCS, and with him studied at St Mary's Hospital, London in 1907 under Almroth Wright and Alexander Fleming. After his years in England, Gilbert went into general practice in Adelaide in partnership with Dr Humphrey Marten. He served on the surgical staff of the Adelaide Children's Hospital and became its President. He went on active service throughout the war of 1914-18. When he was President of the South Australian branch of the British Medical Association he inaugurated its Postgraduate Committee, which later instigated the University of Adelaide to form a Medical Postgraduate Committee. He was also for many years President of the Medical Benevolent Association of South Australia. He was honorary medical adviser to HRH the Duke of Gloucester in South Australia, 1934. Gilbert married Winifred Short, grand-daughter of the first Bishop of Adelaide, thus uniting two of the oldest families in the State. They had three sons, who all served in the second world war. Gilbert was a good oar while at College, but later became a keen cricketer, being an excellent slow left-arm bowler. He died on 25 October 1947 at Adelaide, where he had practised at 188 North Terrace.