The Ruetz is a river of Tyrol, Austria, a tributary of the Sill.

The Ruetz flows from the glacier area of the Stubaital to the Wipptal in north-east direction. Near the famous Europa Bridge, it merges with the Sill after a route length of appr. 37 km (23 mi). The river crosses the village of Fulpmes providing a nearby power station of the Austrian Federal Railways with electricity.

As a typical rapid-river the Ruetz is pretty dangerous and full of rapids.