Santa Gadea del Cid is a municipality and town in the province of Burgos, within the autonomous community of Castile and León, Spain. It is a small rural settlement in northern Spain, located in the Ebro river basin near the border with the Basque Country and La Rioja.
According to the 2004 census conducted by Spain's National Statistics Institute (INE), the municipality had a population of 174 inhabitants. This figure reflects the pattern of depopulation common to many small municipalities in rural Castile and León.
The town is historically associated with the medieval Castilian hero Rodrigo Díaz de Vivar, known as El Cid, whose name forms part of the municipality's official title. Its built heritage includes the Church of San Pedro, a Gothic structure with a Romanesque tower, and the remains of a medieval bridge over the Ebro. The surrounding landscape is characterized by farmland and rolling hills typical of the Burgos countryside.