Frederick Ponsonby, 3rd Earl of Bessborough, styled the Viscount Duncannon from 1758 to 1793, was an Anglo-Irish peer.

William Ponsonby, 2nd Earl of Bessborough was a British politician and public servant. He was an Irish and English peer and member of the House of Lords. 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.