Almaraz de Duero is a municipality in the province of Zamora, within the autonomous community of Castile and León, Spain. It lies in the western part of the country, in a region that forms part of the Duero river basin.
The municipality is small, with a population recorded as 435 inhabitants in the 2007 census conducted by Spain's National Statistics Institute (INE). Its name associates it with the Duero, the major river that runs through Zamora province and much of Castile and León.
As a municipality, Almaraz de Duero is one of the many small local administrative units that make up the province of Zamora, a largely rural area of Spain characterised by a scattered pattern of villages and low population densities.