Captain John Augustus Hervey, Lord Hervey, RN (1 January 1757 – 10 January 1796) was a British diplomat.
Hervey was the eldest surviving son of Frederick Hervey, 4th Earl of Bristol and his wife, Elizabeth née Davers (died 1800). Joining the navy, he was promoted Captain and was at one point the senior naval officer on the St Lawrence River in Quebec. From 1787 to 1794, he was Minister to Tuscany. On 4 October 1779, he married Elizabeth Drummond (died 4 September 1818), the eldest daughter of Colin Drummond, of Megginch Castle, Perthshire, who was Commissary-General and Paymaster to the Forces in Canada. They had a daughter, Hon. Elizabeth Catherine Caroline (1780–1803), who married Charles Ellis, 1st Baron Seaford. On his death in 1796, his courtesy title was assumed by his brother, Frederick.