Jordan's Castle (Irish Language: Caisleán MacSiurtain), (Ulster Scots: Joardan's Kessel) is a castle situated in Ardglass, County Down, Northern Ireland. The tower house known as Jordan's Castle is a State Care Historic Monument sited in the townland of Ardglass, in Down District Council area, at grid ref: J5601 3713. It stands close to the junction of Kildare and Quay Streets in Ardglass and commands the harbour.