In Spain, a comarca (Spanish: [koˈmaɾka] ⓘ)[a] is either a traditional territorial division without any formal basis, or a group of municipalities, legally defined by an autonomous community for the purpose of providing common local government services.

The large majority of legally defined comarcas are in Catalonia (42) and Aragon (33), and are regulated by law and are governed by a comarcal council with specified powers.

There are seven comarcas formally registered in Basque Country and one, El Bierzo, in Castile and León.

In other regions, comarcas are traditional or historical or in some cases, contemporary creations designed for tourism promotions.

[3] In such comarcas or natural regions municipalities have resorted to organizing themselves in mancomunidad (commonwealth), like the Taula del Sénia, the only legal formula that has allowed those comarcas to manage their public municipal resources meaningfully.