John Saunders Gilliat (24 November 1829 – 11 February 1912) was a British banker and Conservative politician. He was the son of and Mary Anne Saunders of Fernill, Berkshire. His father was founder J K Gilliat and Company, a merchant banking company that traded in England and America. He was educated at Harrow School and University College, Oxford. On his death at the age of 82 in 1912 Gilliat was the oldest member of the Court of the Bank of England.