George Sackville, 4th Duke of Dorset
George John Frederick Sackville, 4th Duke of Dorset, styled Earl of Middlesex
until 1799, was a British nobleman.
The only son of John Sackville, 3rd Duke of Dorset and his wife Arabella, he was educated at Harrow and Christ Church, Oxford, receiving a MA from the latter on 30 June 1813.
He was appointed High Steward of Stratford-on-Avon, and was commissioned a captain of the local militia on 27 April 1813. On 26 July 1813, he was made lieutenant-colonel commandant of the Sevenoaks and Bromley battalion of militia. However, he died in February 1815, of a fall from his horse while hunting on Killiney Hill in County Dublin. He had no children, so he was succeeded as duke by his cousin Charles Sackville-Germain. His estate of Knole passed to his sister Elizabeth Sackville-West, Countess De La Warr.