Bonndorf is a town in the Waldshut district in Baden-Württemberg, Germany. It is situated in the southern Black Forest, 14 km southeast of Titisee-Neustadt. It comprises the villages Boll, Brunnadern, Dillendorf, Ebnet, Gündelwangen, Holzschlag, Wellendingen and Wittlekofen. The town is well known for its Fastnacht festival held on the days before Ash Wednesday. Wellendingen has its Frogs in the parade.