Castronuevo is a municipality in the province of Zamora, within the autonomous community of Castile and León, Spain. It is located in the northwestern part of the country, in a region characterised by the flat, agricultural terrain of the Duero basin.
The municipality is small, with a population recorded as 312 inhabitants in the 2009 census conducted by Spain's National Statistics Institute (INE). Like many rural settlements in the province of Zamora, it is part of a sparsely populated area where agriculture has traditionally formed the basis of the local economy.
Castronuevo is one of numerous small municipalities that make up the province of Zamora, a territory known for its historic towns and its position within the broader Castile and León region. The village's modest size and rural setting reflect the demographic patterns typical of this part of inland Spain.