Narrow Water Castle is a 16th-century tower house and bawn near Warrenpoint in Northern Ireland. It is beside the A2 road and on the County Down bank of the Clanrye (Newry) River, which enters Carlingford Lough a mile to the south. It is a historic monument in state care in the townland of Narrow Water, in Newry and Mourne District Council district, at grid ref: J1256 1939.