Foz do Douro (Portuguese pronunciation: [ˈfɔʒ ðu ˈðoɾu]; meaning "Mouth of the Douro") is a former civil parish in the municipality of Porto, Portugal.

It is located in the western part of Porto, next to the mouth of the Douro river and the Atlantic Ocean.

The first king of Portugal, Afonso Henriques, donated a chapel in São João da Foz in 1145.

In the 13th century the chapel became part of the Benedictine monastery of Santo Tirso.

The borders of the parish, called Couto da Foz, were limited by the city of Bouças (Matosinhos) in the north and Porto, to the east.