Kortezubi is a town and municipality in the province of Biscay, part of the Basque Autonomous Community in northern Spain. It is a small settlement, with a population recorded at 444 inhabitants.
The municipality is situated within the historic and cultural region of the Basque Country, an area known for its distinct language and traditions. As a municipality, Kortezubi serves as a local administrative unit encompassing the town and its surrounding area.
Its modest size places it among the smaller municipalities of Biscay, and its identity is tied to the rural and cultural landscape of the province.