The Castle of Arnóia (Portuguese: Castelo de Arnóia) is a medieval castle in civil parish of Arnóia, municipality of Celorico de Basto, the district of Braga.

A view of the castle fortifications and keep tower of the Castle of Arnoia

It is classified as a National Monument.

41°21′49″N 8°03′07″W / 41.36361°N 8.05194°W / 41.36361; -8.05194