Bocos de Duero is a village and municipality in the province of Valladolid, within the autonomous community of Castile and León, Spain. It lies in the Duero river basin, from which it takes the second part of its name.
The municipality covers an area of 6.34 square kilometres (2.45 square miles). As of 2011, its population was 63 people, making it a small rural settlement with a low population density.