Boylagh (Irish: Baollaigh[l 1]) is a historic barony in County Donegal in Ireland.

[1] Patrick Weston Joyce said the name Boylagh comes from the territory of the O'Boyles.

[3] Boylagh is bordered by the baronies of Kilmacrenan to the north east, Rapboe South to the east, and Banagh to the south; to the north and west is the Atlantic Ocean.

[4] The barony contains the following civil parishes:[1] Settlements in the barony include Annagry,[l 2] Burtonport,[l 2] Doochary,[l 3] Dungloe,[l 2] Glenties,[l 2] Kilrean,[l 3] Lettermacaward,[l 3] Portnoo,[l 3] and Ranafast.

[l 4] The barony is thus described in the Parliamentary Gazetteer of 1846:[5] From "Irish placenames database".