The Saalach Valley (German: Saalachtal) is the name of the middle and upper reaches of the Saalach, a mountain river in the Austrian state of Salzburg (Pinzgau and Flachgau regions) and the southern part of the German state of Bavaria (in Berchtesgadener Land).
The main valley is about 70 km long and begins north of the Zeller See. It forms the broad vale of the Saalfelden Basin, the heart of the Saalachpinzgau region. Initially it separates the Kitzbühel Alps in the west, from where the Saalach originates, from the Salzburg Slate Alps in the east; later, it divides the Loferer Steinberge and the Chiemgau Alps in the west from the Berchtesgaden Alps in the east. Near Reichenhall and Großgmain the valley broadens again and ends between Freilassing and Salzburg, the Saalach flowing for its last few kilometres through the plain of the Salzburg-Freilassing Basin.
The roughly 30 km long upper reaches of the Saalach is not called the Saalachtal, but bears the name Glemmtal, the area of its source streams being called Hinterglemm.
The Saalach Valley was formed by the Salzach-Saalach Glacier. When it retreated the glacier left behind thick sheets of morainic debris about 10,000 years ago that extend from the Zeller See in the north to just in front of Saalfelden, roughly by the Kühbichl (875 m). In the post-glacial period, the Saalach flowed into the Zeller See and then into the Salzach river to the south. The drift deposits from the Glemmtal, that were laid down between the Zeller See and Maishofen as gravel, blocked the southerly course of the Saalach and force it to flow northwards along its present riverbed. This has been evinced by excavations between Atzing and Unterreit.