Ribadeo is a municipality in the Spanish province of Lugo in Galicia. It has a population of 10,023 (INE, 2011) and an area of 106.2 km² (41.0 sq mi). It is the capital of the A Mariña Oriental comarca.

The municipality of Ribadeo has approximately the shape of a 10x10 kilometer square. It is bordered to the north by the Cantabrian Sea, to the east by the Ribadeo estuary (on the other side of which is Castropol in Asturias), to the west by the municipality of Barreiros and to the south by that of Trabada. The capital of the municipality is the town of Ribadeo. There is one other town - Rinlo - and many small villages and hamlets. The highest point of the municipality is the mountain of Mondigo (571 m (1,873 ft)), in the parish of Cubelas.