William Lithgow (1 January 1784 – 11 June 1864) was educated at the University of Edinburgh, graduating as a Licentiate of the Church of Scotland. William Lithgow was the Auditor General of the colony of New South Wales in Australia.
Lithgow was born in Scotland. He was an appointed member of the New South Wales Legislative Council from 30 January 1829 to 20 June 1848. He was Auditor General from 8 November 1824 to 30 April 1852. The city of Lithgow in New South Wales was named in honour of William Lithgow by his friend, Surveyor-General John Oxley. Lithgow died in St Leonards, New South Wales.