The Afon Dulas is a river in Powys, Wales (Afon is Welsh for river). It is a headwater tributary of the River Severn, which it joins at Llanidloes opposite the confluence with the Afon Clywedog. Its principal tributary is the Afon Brochan. The total length of the Dulas and Brochan is 19.6 km. Other tributaries include Nant Cydros, the Rhydyclwydau Brook and Nant Gynwydd.
