William Dowdeswell PC (12 March 1721 – 6 February 1775)[1] was a British politician who was a leader of the Rockingham Whig faction.

A son of William Dowdeswell of Pull Court, Bushley, Worcestershire, he was educated at Westminster School, at Christ Church, Oxford, then at the University of Leiden.

He spent the summer of 1746 with him at the Heeze-Leende estate of his uncle, Messire François-Adam, Baron d'Holbach, Seigneur de Heeze, Leende et autres Lieux (ca.

Becoming prominent among the Whigs, Dowdeswell was made Chancellor of the Exchequer in 1765 under the Marquess of Rockingham, and his short tenure of this position appears to have been a successful one, he being in Lecky's words a good financier, but nothing more.

Dowdeswell then led the Rockingham party in the House of Commons, taking an active part in debate until his death.