William Benwell was born in Caversham in Oxfordshire and educated at Reading School and Trinity College, Oxford (M.A. 1789, Fellow 1790) where he formed a close friendship with Henry Headley and acquaintances with the younger disciples of Thomas Warton. He was for four years Curate of Sunning in Berkshire before returning to Oxford in 1790 as lecturer and tutor in in Greek. There he edited Xenophon's Memorabilia. Benwell was appointed Rector of Chilton in Suffolk, though he resided in Wiltshire. There he died of a fever contracted while attending the poor, only a few weeks after his marriage.
Xenophon, Memorabilia, ed. Benwell. 1805.