Pareja is a municipality in the province of Guadalajara, within the autonomous community of Castile-La Mancha, Spain. It lies in the central part of the country, in the region historically known as Castile.
According to the 2004 census carried out by Spain's National Statistics Institute (INE), the municipality had a population of 502 inhabitants. This small population figure reflects Pareja's character as a minor rural municipality rather than an urban centre.
As a municipality, Pareja forms part of the local administrative structure of the province of Guadalajara, with its own municipal government. Its small size places it among the many sparsely populated settlements scattered across the Castile-La Mancha region.