William Austin Horn was born in New South Wales but was educated at St Peter's College, Adelaide and Oxford, returning to Australia in 1874 and spending ten years in rough bush life. In 1879 he married Penelope Elizabeth Belt and the couple had two daughters and six sons.
He was involved in the development of mining in the mid-north of SA, and was noted for his famous horse ride of 164 miles in 22 hours from Moonta to Adelaide, beating a rival to register a mining claim (The South Australian Register 27 December 1922, p. 7). He was an early pioneer of the Silverton and Broken Hill mines, and was a Member of the South Australian House of Assembly 1887-1893 and a Justice of the Peace. He was a generous benefactor, donating statues to the city of Adelaide and rare coins to the Museum. He sponsored a major exploring expedition into Central Australia in 1894 and the four-part Report of the Horn Scientific Expedition... (1896), edited by Balwin Spencer, is a major work of Australian science and anthropology.
From 1898 he lived in England, where he published a book of Australian bush verse. The Australian Dictionary of Biography describes him as "'one of the most generous public men' in South Australia".
