Viddalba is a comune (municipality) in the Province of Sassari in the Italian region of Sardinia, located about 190 km north of Cagliari and about 35 km northeast of Sassari. Viddalba borders the following municipalities: Aggius, Badesi, Bortigiadas, Santa Maria Coghinas, Trinità d'Agultu e Vignola, Valledoria. Sights include several domus de janas and nuraghe, a Roman necropolis and remains of a bridge, and the medieval Romanesque church of San Giovanni Evangelista.