The Sanna is a river of Tyrol, Austria, a left tributary of the Inn.
The Sanna is formed near Tobadill by the confluence of the rivers
(, from Arlberg and the valley ) and
(, from Silvretta and Paznaun). It flows into the Inn at the small town of Landeck. It is long. Its basin area is . The villages Pians and Grins are situated at its waterfront.
The whitewater river is used for kayaking and was the site of the 1996 world championships.