Campillo de Ranas is a municipality in the province of Guadalajara, in the autonomous community of Castile-La Mancha, Spain. It is a small rural settlement in the Spanish interior, situated within the comarca of the Sierra Norte de Guadalajara.
The municipality is sparsely populated. According to the 2004 census carried out by the Instituto Nacional de Estadística (INE), Campillo de Ranas had a population of 184 inhabitants. This figure reflects the low population density typical of many villages in this part of Castile-La Mancha.
As a municipality, Campillo de Ranas is the basic unit of local administration in Spain, encompassing the village itself and its surrounding territory. Its location in the province of Guadalajara places it within the wider Castile-La Mancha region, one of the country's largest autonomous communities by area.