On 25 May 1921, during the Irish War of Independence, the Custom House in Dublin was occupied and then burnt in an operation by the Irish Republican Army (IRA). The Custom House was the headquarters of the Local Government Board for Ireland, an agency of the British administration in Ireland, against which the IRA was fighting in the name of the self-proclaimed Irish Republic. The operation, involving over 100 IRA volunteers, was a propaganda coup for the republicans but a military disaster for the IRA in the Irish capital. A force of British Auxiliaries quickly arrived and a gun battle erupted. Five IRA volunteers were killed, along with three civilians, and about 80 volunteers were captured.

The Custom House is a neoclassical 18th century building in Dublin, Ireland which houses the Department of Housing, Local Government and Heritage. It is located on the north bank of the River Liffey, on Custom House Quay between Butt Bridge and Talbot Memorial Bridge.