William Peter (22 March 1788 - 6 February 1853) was a British diplomat and Liberal politician who sat in the House of Commons from 1832 to 1835.
Peter was born at Harlyn, St Merryn, Cornwall, the son of Henry Peter and his wife Anna Maria. He was educated at Oxford University receiving BA in 1807 and MA in 1809. He was called to the bar on 28 May 1813. After a few years in London, he returned to Cornwall where he was a J.P. and Deputy Lieutenant. He complied a two volume set of Speeches of Sir Samuel Romilly in the House of Commons, published in 1820.