Granville Leveson Proby, 4th Earl of Carysfort KP PC (14 September 1824 – 18 May 1872), styled Lord Proby from 1858 to 1868, was a British Liberal politician. He notably held office as Comptroller of the Household between 1859 and 1866.

Proby was born at Bushey Park, Enniskerry, County Wicklow, the second son of Admiral Granville Leveson Proby, 3rd Earl of Carysfort, by Isabella Howard, daughter of the Honourable Hugh Howard. He became known by the courtesy title Lord Proby in 1858 on the death of his elder brother. He served with the 74th Regiment of Foot and achieved the rank of captain.^{[citation needed]}

In 1858 Proby was elected to the House of Commons for County Wicklow,^[1] and served under Lord Palmerston and then Lord Russell as Comptroller of the Household from 1859^[2] to 1866.^[3] In 1868 he succeeded his father in the earldom and entered the House of Lords. He was admitted to the Privy Council in 1859^[4] and made a Knight of the Order of St Patrick in 1869.^[5]

Lord Carysfort married Lady Augusta Maria Hare, daughter of William Hare, 2nd Earl of Listowel, in 1853. The marriage was childless. He died in Florence, Italy, in May 1872, aged 47, and was succeeded in his titles by his younger brother, William. The Countess of Carysfort died at Grosvenor Crescent, London, in March 1881, aged 48.^{[citation needed]}