The Isar () is a river in Austria and in Bavaria, Germany. Its source is in the Karwendel mountain range of the Alps. The Isar river enters Germany near Mittenwald and flows through Bad Tölz, Munich, and Landshut before reaching the Danube near Deggendorf. With 295 km length, it is among the longest rivers in Bavaria. It is Germany's second most important tributary of the Danube.
