The Mitford family is an aristocratic English family whose principal line had its seats at Mitford, Northumberland. Several heads of the family served as High Sheriff of Northumberland. A junior line, with seats at Newton Park, Northumberland, and Exbury House, Hampshire, descends via the historian William Mitford (1744–1827) and were twice elevated to the British peerage, in 1802 and 1902, under the title Baron Redesdale.

William Mitford was an English historian, landowner, and politician. His best known work is The History of Greece, published in ten volumes between 1784 and 1810.