The 7th Duke of Devonshire.

William Cavendish, 7th Duke of Devonshire, KG, PC (27 April 1808 – 21 December 1891), known as Lord Cavendish of Keighley between 1831 and 1834 and 2nd Earl of Burlington of the 2nd creation between 1834 and 1858, was the great-grandson of the 4th Duke of Devonshire, grandson of the 1st Earl of Burlington, and son of William Cavendish.

He was educated at Eton and Trinity College, Cambridge. He succeeded his grandfather as Earl of Burlington (2nd creation) in 1834 before succeeding his cousin as Duke of Devonshire in 1858. In 1829, he married a niece of the 6th Duke, Lady Blanche Howard.

He was Chancellor of the University of London from 1836 to 1856, and then Chancellor of the University of Cambridge from 1861 to 1891. At Cambridge he endowed the building of the Cavendish Laboratory, and it was named after him. He made vast (and ultimately unsuccessful) investments in heavy industry at Barrow-in-Furness, and had his nearby country house Holker Hall rebuilt in its present form after it was gutted by a fire in 1871. The 7th Duke inherited a considerable amount of property in Eastbourne from his grandfather Lord George Augustus Henry Cavendish, and his wife Elizabeth Compton. He saw through the development of Eastbourne in the 19th century with its parks, baths and squares and is commemorated by a statue at the top of Devonshire Place.

The Duke's three surviving sons became Members of Parliament: the eldest, known after 1858 by the courtesy title the Marquess of Hartington, MP for Lancashire North 1857–91, led the Liberal Party and was asked three times to be Prime Minister by Queen Victoria (he succeeded his father as 8th Duke in 1891); Lord Frederick Cavendish was MP for the West Riding and Chief Secretary for Ireland and was assassinated in 1882; Lord Edward Cavendish was MP for West Derbyshire. He also had one son, Hon. William (8 October 1831 – 15 May 1834) who died as an infant, and a daughter, Lady Louisa Caroline (d. 21 September 1907), who married Adm. Hon. Francis Egerton and had issue.