John Townshend, 2nd Viscount Sydney

John Thomas Townshend, 2nd Viscount Sydney of St Leonards (21 February 1764 – 20 January 1831) was a British peer and Member of Parliament.

He was the eldest son of Thomas Townshend, 1st Viscount Sydney of St Leonards and Elizabeth Powys and was educated at Eton School (1775–81) and Clare College, Cambridge. He went on the Grand Tour in 1785.

In 1786 he was elected as the Hon. John Townsend the Member of Parliament for Newport, Isle of Wight, sitting from 1786 to 1790. He then sat for Whitchurch from 1790 to 1800. He inherited his peerage on the death of his father in 1800.

He was Under-Secretary of State for Home affairs from 1784 to 1789, a Lord of the Admiralty from 1789 to 1793, a Lord of the Treasury from 1793 to 1800, and a Lord of the Bedchamber from 1800 to 1810. He was also Ranger of Hyde Park and Ranger of St. James’s Park from 1807 to his death.

His death in 1831 was viewed by the family "as a great release from hopeless suffering". He had married twice. On 13 April 1790 he married Hon. Sophia Southwell, daughter of Edward Southwell, 20th Baron de Clifford. They had one child; He married a second time, to Caroline Elizabeth Letitia Clements, daughter of Robert Clements, 1st Earl of Leitrim, on 27 May 1802. They had two children:
 * Hon. Sophia Mary Townshend (d. 6 Dec 1852).
 * Mary Elizabeth Sydney (d. 25 Dec 1847), married 1) George James Cholmondeley (b. 22 Feb 1752, d. 5 Nov 1830) 2) Charles Marsham, 2nd Earl of Romney
 * John Robert Townshend, 1st Earl Sydney (b. 9 Aug 1805, d. 14 Feb 1890)