From the mountain, the river flows south to Dinas Mawddwy and down through great fields entering Montgomeryshire where it collects the waters of the River Angell at Aberangell. It continues south to Cemmaes Road, and southwest past Machynlleth, where it collects the waters of the River South Dulas from the south and then the River North Dulas from the north, assuming thereafter the latter's office of boundary river between Montgomeryshire and Merionethshire.
Just a few miles below Machynlleth the Dovey becomes tidal.
The lowest bridge on the river is the railway bridge by Dovey Junction station, a few yards below which the river leaves Montgomeryshire behind; the estuary opens up and becomes a great sea-loch parting Merioneth from Cardiganshire, opening finally into Cardigan Bay at Aberdovey.
The only large town on the Dovey is Machynlleth in Montgomeryshire.
Because of its source high in the Cambrian Mountains and its relatively short length, the Dovey is prone to flooding and some roads in the lower catchment can become impassable during very wet weather. It is a very clean river with little pollution befouling its waters and is rich in salmon and sea trout, which latter are migratory brown trout).
Amongst the tributaries of the Dovey are: