The Constitution of the Irish Free State was adopted by Act of Dáil Éireann sitting as a constituent assembly on 25 October 1922. In accordance with Article 83 of the Constitution, the Irish Free State Constitution Act 1922 of the British Parliament, which came into effect upon receiving the royal assent on 5 December 1922, provided that the Constitution would come into effect upon the issue of a Royal Proclamation, which was done on 6 December 1922. In 1937 the Constitution of the Irish Free State was replaced by the modern Constitution of Ireland following a referendum.

The Constitution of Ireland is the fundamental law of Ireland. It asserts the national sovereignty of the Irish people. The constitution, based on a system of representative democracy, is broadly within the tradition of liberal democracy. It guarantees certain fundamental rights, along with a popularly elected non-executive president, a bicameral parliament, a separation of powers and judicial review.