William Eliot, 2nd Earl of St Germans (1 April 1767 – 19 January 1845), known as William Elliot until 1823, was a British diplomat and politician.
Eliot was born at Port Eliot, Cornwall, the third son of Edward Craggs-Eliot, 1st Baron Eliot and his wife Catherine (née Elliston). He was educated at Pembroke College, Cambridge, taking an M.A. in 1786. From November 1791 until 1793 he was a Secretary of Legation at Berlin, from 1793 to 1794 Secretary of Embassy and Minister Plenipotentiary at The Hague and from 1796 Minister Plenipotentiary to the Elector Palatine and to the Diet of Ratisbon. Eliot also sat as Tory Member of Parliament for St Germans from 1791 to 1802 and for Liskeard from 1802 to 1823 and served as a Lord of the Admiralty from 1800 to 1804 and as Parliamentary Under-Secretary of State for Foreign Affairs from 1804 to 1805. In 1823 he succeeded his elder brother as second Earl of St Germans and entered the House of Lords.
Lord St Germans married four times.