Viamala or Via Mala (Romansh: literally, "bad path") is a narrow gorge along the river Hinterrhein between Zillis-Reischen and Thusis in the Canton of Graubünden, Switzerland , as well as the ancient and notorious pathway which traverses the gorge. Historically the Viamala was the most serious obstacle on the approach to the Splügen and San Bernardino mountain passes.

A Viamala pathway already existed in Roman antiquity, though it is unclear whether it was only a foot and bridle path, or also passable by wagons. Two access paths met at the northern entrance to the Viamala gorge, which the Romans traversed by means of several rock galleries cut into the gorge's left walls. The Romans also constructed a wooden bridge crossing over to the right side of the Hinterrhein, routing traffic via Reischen to Zillis. Presumably this bridge was located somewhere below today's automobile bridge near the existing Pùnt da Suransuns pedestrian bridge.