John Stewart Gathorne-Hardy, 2nd Earl of Cranbrook, VD, JP, DL (22 March 1839 – 13 July 1911) was a British hereditary peer, Conservative politician, and military officer.

Born John Stewart Hardy, Lord Cranbrook was the eldest son of the Conservative politician Gathorne Gathorne-Hardy, 1st Earl of Cranbrook, and Jane Stewart Orr. He assumed the additional surname of Gathorne by Royal licence in 1878 and when his father was elevated to the peerage as Earl of Cranbrook in 1892, he gained the courtesy title of Lord Medway.^[1]

Cranbrook was educated at Eton and Christ Church, Oxford.^[2]

Cranbrook was elected to the House of Commons for Rye in 1868, a seat he held until 1880, and later represented Mid Kent from 1884 to 1885 and Medway from 1885 to 1892. He gained the rank of Lieutenant in the Rifle Brigade. He was made an honorary Colonel in the 5th Weald of Kent Battalion, The Buffs. He was Deputy lieutenant and Justice of the peace, as well as County Alderman, for Kent.^[2]

In 1906, he succeeded his father as second Earl of Cranbrook and took his seat in the House of Lords.

In 1867 at Plaxtol, Lord Cranbrook married Cicely Marguerite Wilhelmina Ridgway, daughter of Joseph Ridgway and Selina Harriet Doyle. They had seven children:^[3][4][5]

• Lady Selina Marguerite Gathorne-Hardy (1870 – 29 May 1934)
• Gathorne Gathorne-Hardy, 3rd Earl of Cranbrook (18 December 1870 – 23 December 1915)
• Lady Jane Ethel Gathorne-Hardy (1872 – 26 January 1943)
• Gen. Hon. Sir John Francis Gathorne-Hardy (14 January 1874 – 21 August 1949)
• Cdr. Hon. Ralph Cecil North Gathorne-Hardy (19 March 1876 – 30 December 1911)
• Lt.-Col. Hon. Nigel Charles Gathorne-Hardy (31 March 1880 – 17 December 1958)
• Lady Dorothy Milner Gathorne-Hardy (4 January 1889 – 21 February 1977), married Rupert D'Oyly Carte, proprietor of the Savoy Hotel

Lord Cranbrook died in July 1911 at the age of 72 and was succeeded in the earldom by his eldest son, Gathorne. Lady Cranbrook died in 1931.^[2]