Porto do Son (Galician pronunciation: [ˈpɔɾtʊ ðʊ ˈsoŋ]) is a municipality in the province of A Coruña, in the autonomous community of Galicia, Spain.

Porto do Son occupies the north-eastern side of the Barbanza Peninsula, and thus borders the municipalities of the Shire of Barbanza, Boiro, A Pobra do Caramiñal and Santa Uxía de Ribeira.

This is the largest municipality in Barbanza, and its highest point is mount Iroite.

Just south of the fishing village of "Porto do Son" there are the 2000-year-old ruins of a Celtic fort at "Castro de Baroña".

Local legend states that any person who sees the image or shape of a lion's head in the Castro de Baroña rock formations will be chosen to join the rebirth of the Celtic Clan of Baroña.