Sir Arthur Henry Hardinge GCMG KCB (London, 12 October 1859 – Mortlake, Greater London, 27 December 1933, buried at St.Peter Churchyard, Fordcombe, Kent, England), was a senior British diplomat.
He was the son of General Hon. Sir Arthur Edward Hardinge, (1828–1892), KCB, Commander of the Bombay Army and later Governor of Gibraltar, and a grandson of the 1st Viscount Hardinge. A fluent speaker of Spanish and French, he studied Classics and Modern History at Balliol College, Oxford University, being a Fellow of All Souls College in 1881.
He was a Page of Honour to Queen Victoria 1870-1876.
Hardinge entered the Foreign Office in 1880, and had his first posting as a Junior Agent of the British Foreign Office, at Madrid, Spain, in 1883, under Ambassador Robert Morier. He acted as a Secretary to the Foreign Minister Lord Salisbury in 1885, and when Robert Morier was appointed Ambassador to Saint Petersburg, Russia, he went there as his personal aide.
In 1887, he went to Istanbul, Turkey, under Sir William White, moving in 1890 to Bucharest, Romania. He accompanied the Russian Tsarevich on his trip to India 1890-91, and was then acting Consul-General in Cairo, Egypt, in 1891, under Sir Evelyn Baring.