William Wentworth, 2nd Earl of Strafford (17 March 1722 – 10 March 1791), styled Viscount Wentworth until 1739 was a peer and member of the House of Lords of Great Britain.
Strafford was the only son of Thomas Wentworth, 1st Earl of Strafford (1672-1739). His paternal great-grandfather was Sir William Wentworth of Ashby Puerorum, a younger brother of Thomas Wentworth, 1st Earl of Strafford of an earlier creation. His father was a cousin of William Wentworth, 2nd Earl of Strafford, who died childless, on whose death in 1695 he became the 3rd Baron Raby. However, the Strafford fortune, with the estate of the great Jacobean house of Wentworth Woodhouse, went to a nephew of the second Earl's by marriage.
The title of Earl of Strafford was created for the third time in 1711, for Strafford's father, and thus came to him on his father's death in 1739. He was also 2nd Duke of Strafford in the Jacobite Peerage. He played less of a political role than his father, although he was granted a farm of the post fines on 25 March 1756 and was appointed a deputy lieutenant of the West Riding of Yorkshire on 4 August 1757.
Strafford added a neo-Palladian range to Wentworth Castle, his country house in Yorkshire, a project begun in 1759 and completed in 1764. As its principal designer, this gained him an entry in Colvin's Biographical Dictionary of British Architects. Strafford's friend Horace Walpole described this south front on 2 August 1770, as showing "the most perfect taste in architecture":
In 1741, Strafford married Lady Anne Campbell (born about 1715, died 1785), the second of the five daughters of John Campbell, 2nd Duke of Argyll. The two became part of a social set which included Horace Walpole, who considered the countess to be a "vast beauty" and immortalised her in a poem which was published in 1765.