An Garda Síochána (meaning “the Guardian of the Peace”), more commonly referred to as the Gardaí (“Guardians”), is the police force of Ireland. The service is headed by the Commissioner of An Garda Síochána who is appointed by the Irish government. Its headquarters are in Dublin’s Phoenix Park.

The force was originally named the Civic Guard in English, but in 1923 it became An Garda Síochána in both English and Irish (The Guardian(s) of the Peace”). Garda Síochána na hÉireann (“of Ireland”) appears on its logo but is seldom used elsewhere.

The Civic Guard was formed by the Provisional Government in February 1922 to take over the responsibility of policing the fledgling Irish Free State. It replaced the Royal Irish Constabulary (RIC) and the Irish Republican Police of 1919–22. In August 1922 the force accompanied Michael Collins when he met the Lord Lieutenant in Dublin Castle.

An Garda Síochána (Temporary Provisions) Act 1923 enacted after the creation of the Irish Free State on 8 August 1923, provided for the creation of “a force of police to be called and known as ‘An Garda Síochána’”. Under section 22, The Civic Guard were deemed to have been established under and to be governed by the Act. The law therefore effectively renamed the existing force.

During the Civil War of 1922–23, the new Free State set up the Criminal Investigation Department as an armed, plain-clothed counter-insurgency unit. It was disbanded after the end of the war in October 1923 and elements of it were absorbed into the Dublin Metropolitan Police.

In Dublin, policing remained the responsibility of the Dublin Metropolitan Police (DMP, founded 1836) until it merged with An Garda Síochána in 1925. Since then the Gardaí has been the only civil police force in the state now known as Ireland. Other police forces with limited powers are the Military Police within the Irish Defence Forces, the Airport Police Service, and Dublin Port and Dún Laoghaire Harbour police forces.