Born at Nalpa Station, Wellington, South Australia on 30 July 1871, son of Josiah Bonnin the station manager and his wife, *née* Frew. He was educated at Glenelg Grammar School and Adelaide University, where he graduated in 1895. He spent the next three years in London, taking the Conjoint qualification in 1897, and the Fellowship in 1898. He then returned to Australia and practised at 48 Mills Terrace, North Adelaide, where he was succeeded by his son, Josiah Mark Bonnin, MRCP. He lived latterly at 139 Hill Street, North Adelaide. Other medical members of his family were Captain Noel James Bonnin, FRCS, FRACS, who practised at 188 North Terrace, Adelaide, and Josiah Grant Bonnin, FRCS, of Newmarket and London. J A Bonnin was a foundation Fellow of the Royal Australasian College of Surgeons. He married in 1908 Winifred Turpin, and died at Adelaide in October 1945, survived by his five sons and two daughters.