Milmarcos is a municipality in Spain, located in the province of Guadalajara within the autonomous community of Castile-La Mancha.
According to the 2004 census conducted by the Instituto Nacional de Estadística (INE), the municipality had a population of 125 inhabitants. This small population figure reflects the pattern of rural depopulation common to many municipalities in the Guadalajara province.
As a municipality, Milmarcos holds the administrative status of a local entity within the Spanish system of government, encompassing its surrounding territory and resident population under a local administration.