The Honourable (Ralph) Edward Gathorne-Hardy (4 June 1901 – 18 June 1978) was a British Bohemian socialite.
The second child of Gathorne Gathorne-Hardy, 3rd Earl of Cranbrook by his wife Lady Dorothy Boyle, the daughter of David Boyle, 7th Earl of Glasgow, he was educated at Eton and Christ Church, Oxford.
One of the group designated by the press the 'Bright Young People' in the 1920s, he shared a flat with Brian Howard at 39 Maddox Street in London, which was so run-down that fungus grew on the dilapidated staircase. Although he was a respected antiquarian, specialising in 18th-century literature, and worked as a director and rare book expert for the booksellers Elkin Mathews alongside his brother Robert, he remained impecunious, largely living off his elder brother, John David Gathorne-Hardy, 4th Earl of Cranbrook. He also worked at various colleges and for the British Council.
Gathorne-Hardy's sister, Anne (1911-2006), was the wife of George Heywood Hill, owner of the Mayfair bookshop bearing his name. A nephew- son of his younger brother Anthony- was Jonathan Gathorne-Hardy.
- The Plantagenet Roll of the Blood Royal, Clarence Volume I, the Marquis de Ruvigny, pg 274
- Dod's Peerage, Baronetage and Knightage of Great Britain and Ireland, S. Low, Marston & Co., 1923, pg 217
- The Rare Book Game, George Sims, Holmes Publishing Company, 1985, p. 131
- Burke's Peerage, Baronetage and Knightage, 2003, vol. 1, p. 942