Sir John Leslie, 1st Baronet

Sir John Leslie, 1st Baronet (16 December 1822 – 23 January 1916) was a Conservative Member of Parliament for Monaghan from 1871 to 1880. He succeeded his elder brother, Charles Powell Leslie III, in that role.

In 1830, he was sent to school at Dedham, Essex. During midsummer term, 1834, he joined his elder brother, Charles, at Harrow. In 1839, John entered Christ Church, Oxford. He obtained a commission in the 1st Lifeguards, and was quartered at the Regent's, Hyde Park, Windsor and Farnborough barracks.

In 1854, he met at Hazelwood a distinguished Waterloo veteran, Colonel George Dawson-Damer (younger brother of the 2nd Earl of Portarlington), and his daughter, Constance. Leslie married Miss Damer two years later at St George's, Hanover Square, London. His new mother-in-law, Mrs Damer ("Minnie Seymour"), was the adopted daughter of George IV's wife, Maria, Mrs Fitzherbert.