Killowen (from Irish Cill Eoghain, meaning "Eoghain's church", now spelt Cill Eoin), alternatively spelt Cill Abhainn is a small village in County Down, Northern Ireland. It is near Rostrevor and on the shore of Carlingford Lough. In the 2001 Census it had a population of 159 people. It lies within the Newry and Mourne District Council area.
Near Killowen, on the shore of the loch, is Ballinran Court Tomb. It was excavated in 1976 in advance of a road widening scheme.
Killowen was formerly occupied by smallholders and fishermen and was described in The Picturesque Handbook to Carlingford Bay (1846) as "The nursery of the seamen who man the commercial Navy of Newry".
Coordinates: 54°04′30.86″N 6°10′52.83″W / 54.0752389°N 6.1813417°W