William Ponsonby, 2nd Earl of Bessborough

The Earl of Bessborough
William Ponsonby by Sir Joshua Reynolds
Spouse(s)	Caroline Cavendish
Father	Brabazon Ponsonby, 1st Earl of Bessborough
Mother	Sarah Margetson
Born	1704
Died	11 March 1793 (age 89)

William Ponsonby, 2nd Earl of Bessborough PC PC (1704 – 11 March 1793) was a British politician and public servant. He was an Irish and English peer and member of the House of Lords (styled Hon. William Ponsonby from 1723 to 1739 and Viscount Duncannon from 1739 to 1758). He served in both the Irish and the British House of Commons, before entering the House of Lords, and held office as a Lord Commissioner of the Admiralty, Lord Commissioner of the Treasury, and as Postmaster General of the United Kingdom. He was also a Privy Counsellor, Chief Secretary for Ireland and Earl of Bessborough.

In 1725 Ponsonby was returned to the Irish House of Commons for Newtownards and in 1727 for County Kilkenny, holding the seat until 1758, when his father died and he took his father's titles. From 1741 to 1745, he served as Chief Secretary for Ireland under his father-in-law, then Lord Lieutenant of Ireland.

As Viscount Duncannon, Ponsonby was first appointed a Lord Commissioner of the Admiralty on 27 June 1746, a position he held until 1756, when he was appointed a Lord Commissioner of the Treasury. He also represented the British constituencies of Derby from 1742—1754, Saltash from 1754–1756 and Harwick from 1756–1758. Upon the death of his father on 4 July 1758, Ponsonby succeeded him in the House of Lords under the title Baron Ponsonby of Sysonby on 23 November of that year.