Sir William Gell (1777 - 4 February, 1836) was an English classical archaeologist.

Born at Hopton in Derbyshire, he was educated at Jesus College, Cambridge, taking a BA in 1798 and an MA in 1804, and subsequently elected a fellow of Emmanuel College.

About 1800 he was sent on a diplomatic mission to the Ionian islands, and on his return in 1803 he was knighted. He went with Princess (afterwards Queen) Caroline to Italy in 1814 as one of her chamberlains, and gave evidence in her favor at the trial in 1820. He died at Naples in 1836.

His numerous drawings of classical ruins and localities, executed with great detail and exactness, are preserved in the British Museum. Gell was a thorough dilettante, fond of society and possessed of little real scholarship. None the less his topographical works became recognized text-books at a time when Greece and even Italy were but superficially known to English travellers. He was a fellow of the Royal Society and the Society of Antiquaries, and a member of the Institute of France and the Berlin Academy .

His best-known work is Pompeiana; the Topography, Edifices and, Ornaments of Pompeii, published between 1817 and 1832, in the first part of which he was assisted by J. P. Gandy . It was followed in 1834 by the Topography of Rome and its Vicinity. He wrote also Topography of Troy and its Vicinity (1804); Geography and Antiquities of Ithaca (1807); Itinerary of Greece, with a Commentary on Pausanias and Strabo (1810); and Itinerary of the Morea (1816). All these works have been superseded by later publications.