Port Erin is a seaside village in the south-west of the Isle of Man, in the historic parish of Rushen. It was previously a seaside resort before the decline of the tourist trade. Administratively it is designated as a village district, with its own board of commissioners. The district covers around 1 square mile, and is adjacent to: Port St Mary to the south-east; the main part of Arbory and Rushen parish district to the north and east; the sea to the west; and an exclave of Arbory and Rushen parish district to the south. Following recent residential expansion, the settlement is now contiguous with that of Port St Mary, and on 18 July 2018 Tynwald authorised a public enquiry into the proposed expansion of the district boundary to include some of this expansion.

Port St Mary is a village district in the south-west of the Isle of Man. The village takes its name from the former Chapel of St Mary which is thought to have overlooked Chapel Bay in the village. Its population is 1,953 according to the 2011 census. In the 19th century it was sometimes called Port-le-Murray.