The fortified-looking church of Santa María of Baiona, with a Ogival Romanesque style, was built in the 13th century and had the category of collegiate church from 1482 to 1850.

It is divide up in three naves with their respective rectangular apses. The main nave resembles the Cistercian style of Santa María de Oia monastery. Two buttresses flanked the front door in the main façade: three pairs of columns, flat tympanum and archivolts. Windows are Romanesque; there is a marvellous Romanesque rose window up in the main façade. In 1841 several crosses of different styles formerly placed around the village were moved to the portico.