Sir Horace Curzon Plunkett (24 October 1854 – 26 March 1932), was an Anglo-Irish agricultural reformer, pioneer of agricultural cooperatives and author. In politics, he had been elected as a Unionist MP, but later became a supporter of a form of Home Rule and served for a year as a senator in the Irish Free State.
Plunkett, a younger brother of John Plunkett, 17th Baron of Dunsany, was a member of the Congested Districts Board for Ireland for over 27 years, founder of the Recess Committee and the Irish Agricultural Organisation Society (IAOS), vice-president (operational head) of the Department of Agriculture and Technical Instruction (DATI) for Ireland (predecessor to the Department of Agriculture) from October 1899 to May 1907, Unionist MP for South Dublin in the House of Commons of the United Kingdom from 1892 to 1900, and Chairman of the Irish Convention of 1917–18. In 1919 he founded the Irish Dominion League, aiming to keep Ireland united. In 1922 he became a member of the first formation of Seanad Éireann, the upper chamber in the Parliament of the new Irish Free State. He has been described as a Christian socialist.
