The Domleschg is a valley in Graubünden in Switzerland. Geographically, the name "Domleschg" covers both sides of the valley. Politically, the villages on the left bank of the Poserior Rhine form the Kreis (sub-district) of Thusis and those on the right bank form the Kreis of Domleschg. Thusis is the main village in the valley. The northernmost locality is Rothenbrunnen, the southernmost is Sils.