Killeen Castle, located in Dunsany, County Meath, Ireland, is the current construction on a site occupied by a castle since around 1180. The current building is a restoration of a largely 19th century structure, burnt out in 1981.

Dunsany Castle, Dunsany, County Meath, Ireland is a modernised Anglo-Norman castle, started c. 1180 / 1181 by Hugh de Lacy, who also commissioned the original Killeen Castle, nearby, and the famous Trim Castle. It is one of Ireland's oldest homes in continuous occupation, possibly the longest occupied by a single family, having been held by the Cusack family and their descendants by marriage, the Plunketts, from foundation to the present day. The castle is surrounded by its demesne, the inner part of the formerly extensive Dunsany estate. The demesne holds a historic church, a walled garden, a stone farm complex, and an ice house, among other features, and is home to a wide range of fauna.