The Fontanalba is a short mountain river that flows through the Alpes-Maritimes department of southeastern France. It is 4.9 km (3.0 mi) long. It flows in the mountains west of Tende. It is a tributary of the Bieugne, which is a tributary of the Roya. Together with the Vallée des merveilles on the west side of Mont Bégo, the Fontanalba valley forms a protected area, known for Bronze Age petroglyphs.