Cox was born in Wimborne Minster, Dorset in 1764. He married Rebecca Upjohn at Clerkenwell, London in 1789. Cox arrived in NSW on board the "Minerva" in January 1800. Cox became Chief Magistrate at Windsor in 1810 and in July 1814 Governor Macquarie made William Cox the Superintendent of the works for a new road over the Blue Mountains. His first wife died in 1819 and Cox married Anna Blachford in 1821. He died on 15 March 1837.
