William Spain (14 March 1803 – 5 April 1876)[1] was an English lawyer who was appointed in 1841 as a New Zealand Land Claims Commissioner to investigate land purchases from the Māori people by the New Zealand Company. He spent about four years in New Zealand, where he was one of the most highly-paid officials in the colony, before moving to New South Wales where he returned to work as a solicitor, became Inspector-General of Police and a member of the New South Wales Legislative Council.