Foz Arelho is located 8 km from Caldas da Rainha, in the northwest of the county and is bounded to the north by the Atlantic Ocean and the parish of Serra do Bouro.
To the south is limited by the watershed of the Óbidos lagoon and the parish Nadadouro. The boundary between the east by the parishes of the Sierra and Bouro Nadadouro and west by the watershed of the Óbidos lagoon and the Atlantic Ocean.
