The Kitzbühler Ache is a river in the Kitzbühel district, Tyrol, Austria. As Jochberger Ache it sources near Pass Thurn.
Jochberg, Aurach bei Kitzbühel, Kitzbühel and Oberndorf in Tirol are situated along the river. At the southern town limits of St. Johann in Tirol first the Reither Ache flows into the Kitzbühler Ache, later also the Fieberbrunner Ache, forming the Großache, which flows as Tiroler Achen in Bavaria into the Chiemsee. It has a length of app. 66 km.
During the August 2002 European flood, parts of St. Johann in Tirol were affected by the flood due to high water levels of Kitzbühler Ache and Reither Ache.
Coordinates: 47°31′N 12°26′E / 47.517°N 12.433°E