Adsubia (officially L'Atzúbia) is a municipality in the Valencian Community of eastern Spain. It lies in the comarca of Marina Alta, in the north of the province of Alicante.
The town is situated in the northern part of Alicante province, within the Marina Alta district, a comarca that occupies the coastal and inland area of the region's northeast. As a municipality, Adsubia forms part of the Valencian Community, one of Spain's autonomous communities along the Mediterranean coast.
The place is known by two names: Adsubia in Castilian Spanish and L'Atzúbia in Valencian, the latter being its official designation. It is one of the smaller municipalities of the Marina Alta, a predominantly rural and mountainous comarca.