William of Ely was an English churchman and the fifth Lord High Treasurer of England. He was a relative of Richard FitzNeal and supposed descendant of Nigel, Bishop of Ely, both previous Lord High Treasurers. He was appointed a Canon of St. Paul's just before being made Lord High Treasurer in 1196. He added the position of Archdeacon of Cleveland in 1201 and Prebendary of Leighton Buzzard in 1207. A story about William of Ely tells of his attempted escape from England during a time when he had fallen from favour with the King; he was disguised as a commoner but was stopped when he proved unable to respond to a simple question posed to him in English (illustrating the dominance of the French language among nobles and clergymen at the time).