Mary Cavendish Duchess of Devonshire
 Mary Cavendish Duchess of Devonshire GCVO CBE (29 July 1895 Hatfield Hertfordshire – 24 December 1988 Westminster London ) was born Lady Mary Alice Gascoyne-Cecil daughter of James Gascoyne-Cecil 4th Marquess of Salisbury. She was married on 21 April 1917 to Edward Cavendish Lord Hartington who succeeded his father as 10th Duke of Devonshire in 1938 whereupon Mary became Duchess of Devonshire.