Dorothy Cavendish was born 27 August 1750 to William Cavendish, 4th Duke of Devonshire (1720-1764) and Charlotte Elizabeth Boyle, 6th Baroness Clifford (1731-1754) and died 3 June 1794 Burlington House, Piccadilly, Greater London, England, United Kingdom of mortification of the bowels. She married William Henry Bentinck, 3rd Duke of Portland (1738-1809) 8 November 1766 in Burlington House, London, Greater London, England.
|Offspring of William Henry Bentinck, 3rd Duke of Portland and Dorothy Cavendish (1750-1794)|
|William Henry Cavendish-Bentinck, 4th Duke of Portland (1768-1854)||24 June 1768 Welbeck Abbey, Nottinghamshire, England, United Kingdom||27 March 1854 Welbeck Abbey, Nottinghamshire, England, United Kingdom||Henrietta Scott (1774-1844)|
|William Henry Cavendish-Bentinck (1774-1839)|
|Charlotte Cavendish-Bentinck (1775-1862)||3 October 1775||28 July 1862||Charles Greville (1762-1832)|
|Mary Cavendish-Bentinck (1778-)|
|William Charles Augustus Cavendish-Bentinck (1780-1826)||3 October 1780 Welbeck Abbey, Nottinghamshire, England, United Kingdom||28 April 1826 Park Lane, Greater London, England, United Kingdom||Georgiana Augusta Frederica Seymour (c1787-1813) Georgiana Augusta Frederica Seymour (c1787-1813) Anne Wellesley (1788-1875)|
|Frederick Cavendish-Bentinck (1781-1828)|