Bermillo de Sayago (Spanish pronunciation: [beɾˈmiʎo ðe saˈʝaɣo]) is a municipality located in the province of Zamora, Castile and León, Spain.

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.

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).