Dunlewy Lough or Lough Dunlewy (Irish: Loch Dhún Lúiche) is a lake in County Donegal, Ireland. It lies at the foot of Mount Errigal and beside the hamlet of Dunlewey (or Dunlewy). It is separated from the larger Lough Nacung Upper, to the west, by a narrow strip of land. There are the remains of a crannóg (a fortified lake dwelling) on the lake. This may be the source of the name Dún Lúiche, which means "Lugh's fort". There is a modern wooden sculpture of Lugh, an ancient Irish god, on the lakeshore.