John Ponsonby, PC (Ire) (29 March 1713 – 16 August 1787) was an Anglo-Irish politician. He was Speaker of the Irish House of Commons between 1756 and 1771, a period in which the legislative independence of the Kingdom of Ireland was increasingly asserted and tested.
Early life
Ponsonby was the second son of Brabazon Ponsonby, who was created the Earl of Bessborough in 1739, and his first wife, Sarah Margetson Colvill. He was the grandson of William Ponsonby, 1st Viscount Duncannon. He was admitted to Trinity College Dublin on 6 April 1730, but there is no evidence that he ever graduated.
thumb|Ponsonby's townhouse in [[Henrietta Street, Dublin]]
Many of Ponsonby's former allies in the Commons chose to make their peace with the Irish administration, but Ponsonby himself remained in opposition. In 1776 he again stood for election as speaker, but was defeated by the popular incumbent, Edmund Sexton Pery. Ponsonby died, while still a member of parliament, on 16 August 1787.