The Arriaga antzokia in Basque or Teatro Arriaga in Spanish is an opera house in Bilbao, Spain. It was built in Neo-baroque style by architect Joaquín Rucoba in 1890, the same architect that built the city hall. It is named after Juan Crisóstomo de Arriaga, known in his time as the "Spanish Mozart".

The theatre was rebuilt in 1985 after severe flooding in August 1983 destroyed it .