Peñamellera Baja (in Asturian: El Valle Baḥu de Peñamellera) is a municipality in the Autonomous Community of the Principality of Asturias, Spain. It is borderered to the north by Llanes and Ribadedeva, to the west by Peñamellera Alta, and to the east and south by the Autonomous Community of Cantabria.