Duke of Devonshire is a title in the Peerage of England held by members of the Cavendish family. This branch of the Cavendish family has been one of the wealthiest British aristocratic families since the 16th century and has been rivalled in political influence perhaps only by the Marquesses of Salisbury and the Earls of Derby.

Devon is a ceremonial county in South West England. It is bordered by the Bristol Channel to the north, Somerset and Dorset to the east, the English Channel to the south, and Cornwall to the west. The city of Plymouth is the largest settlement, and the city of Exeter is the county town.