John Brown Watt, MLC was a Scottish-born Australian politician. He served as a member of the New South Wales Legislative Council in Sydney, and he was a board member of the Imperial Federation League in London. He was the founder of the Hospital for Sick Children, Glebe, and a director of the Royal Prince Alfred Hospital, and a director of the Sydney Infirmary and Dispensary, and a director of the Colonial Sugar Refining Company, and a director of the Union Bank of Australia.