William Fitzwilliam, 4th Earl Fitzwilliam

The Right Honourable The Earl Fitzwilliam PC
Portrait by William Owen, 1817
Earl Fitzwilliam
In office 10 August 1756 – 8 February 1833
Preceded by	William Fitzwilliam
Succeeded by	Charles Wentworth-Fitzwilliam
Lord Lieutenant of Ireland
In office 13 December 1794 – 13 March 1795
Monarch	George III
Prime Minister	William Pitt the Younger
Preceded by	The Earl of Westmorland
Succeeded by	The Earl Camden
Lord President of the Council
In office 1 July – 17 December 1794
Monarch	George III
Prime Minister	William Pitt the Younger
Preceded by	The Earl Camden
Succeeded by	The Earl of Mansfield
In office 19 February – 8 October 1806
Monarch	George III
Prime Minister	Lord Grenville
Preceded by	The Earl Camden
Succeeded by	Viscount Sidmouth
Personal details
Born	William Wentworth-Fitzwilliam (1748-05-30)30 May 1748
Died	8 February 1833(1833-02-08) (aged 84)
Nationality	British
Political party	Whig
Spouses	Lady Charlotte Ponsonby ​ ​ (m. 1770; died 1822)​ Hon. Louisa Molesworth ​ ​ (m. 1823; died 1824)​
Children	Charles Wentworth-Fitzwilliam, 5th Earl Fitzwilliam
Parents	William Fitzwilliam, 3rd Earl Fitzwilliam Lady Anne Watson-Wentworth

William Wentworth-Fitzwilliam, 4th Earl Fitzwilliam, PC (30 May 1748 – 8 February 1833), styled Viscount Milton until 1756, was a British Whig statesman of the late 18th and early 19th centuries. In 1782 he inherited the estates of his uncle Charles Watson-Wentworth, 2nd Marquess of Rockingham, making him one of the richest people in Britain. He played a leading part in Whig politics until the 1820s.