Seán Treacy (Irish: Seán Ó Treasaigh; né John Allis Treacy; 14 February 1895 – 14 October 1920) was one of the leaders of the Third Tipperary Brigade of the IRA during the Irish War of Independence and one of a small group whose actions initiated that conflict in 1919. He was killed in October 1920, outside No 94 Talbot Street in Dublin in a shootout with British troops during an aborted British Secret Service surveillance operation.
