The Shamrock is a 1777 Irish play or pasticcio opera by John O'Keeffe. It was first staged on 15 April 1777 at Crow Street Theatre in Dublin. According to White (1983),[1] it is unsure whether the work was performed as a straight play or as a pasticcio opera to music by William Shield, as in its altered version as an afterpiece for the London stage, The Poor Soldier (1783).[2]