Castromonte is a municipality in the province of Valladolid, within the autonomous community of Castile and León, Spain. It is a small rural settlement in the region of Castile and León, in north-central Spain.
According to the 2023 census by Spain's National Statistics Institute (INE), Castromonte has a population of 331 inhabitants. The municipality is the birthplace of Olympic sports shooter Domingo Rodríguez.