William Moffat (7 March 1737 – 12 January 1822) was an English banker, merchant and politician. He was involved in several banking partnerships in London, and was also a merchant. By 1790 he lived in Bloomsbury, and in 1799 he bought the Painshill estate in Surrey, but sold it a few years later and lived in Wimbledon. In 1811, as a managing owner of East India Company ships, his business address is given as 27, Nicholas Lane. In 1819, it is 21, Birchin Lane.