Sierra de la Demanda is a comarca located south-east of the province of Burgos in the autonomous community of Castile and León, Spain. It is bounded on the north-east by the Montes de Oca comarca, north-west by the Alfoz de Burgos, south-east by the province of Soria, south-west by the Ribera del Duero comarca, on the east by the province of La Rioja and west by the Arlanza comarca. It is named after the mountain sub-range of Sierra de la Demanda, the northwesternmost end of the Sistema Ibérico.