Bermillo de Sayago (Spanish pronunciation:[beɾˈmiʎoðesaˈʝaɣo]) is a municipality located in the province of Zamora, Castile and León, Spain. According to the 2009 census (INE), the municipality has a population of 1,259 inhabitants. It works as the territorial capital of Sayago, leading this comarca but with no official status. Its central position and the fact of a clearly higher population have given the town this role. Furthermore, the municipalities association Sayagua has its headquarters in Bermillo. This organization is a mancomunidad that supplies services like recycling or water through the comarca of Sayago that could not be afforded by the so-little towns in the area.
Geographically, its landscape is a peneplain, as the rest of Sayago (except Duero canyons, that are relatively far away Bermillo).