47°11′N 7°45′E / 47.183°N 7.750°E The Oberaargau is the region that encompasses the upper watershed of the Aar River in the canton of Bern in Switzerland. On the north, lie the Jura Mountains, and on the south the hills leading to the Emmental.
Administratively, the Oberaargau forms a district within the region Emmental-Oberaargau of the canton of Bern. Historically (until 2009), the Oberaargau comprised the two administrative districts of Wangen and Aarwangen.