Membrillera is a municipality in the province of Guadalajara, within the autonomous community of Castile-La Mancha, Spain. It is a small rural settlement in the central part of the country, situated in the region historically known as the Alcarria.
The municipality is sparsely populated. According to the 2004 census conducted by the Instituto Nacional de Estadística (INE), Membrillera had a population of 113 inhabitants. This figure reflects the pattern of depopulation common to many small villages in inland Spain.
As a municipality, Membrillera holds the administrative status of a municipio, the basic local government unit in Spain, encompassing the village itself and its surrounding territory within the province of Guadalajara.