The Afon Dwyfor is a river in Gwynedd, north-west Wales, in total the river is in length. It rises in Cwm Dwyfor at the head of Cwm Pennant, gathers to itself numerous streams which drain the surrounding mountains from Mynydd Graig Goch in the west to Moel Hebog in the east, then flows southwest towards Dolbenmaen and out of the Snowdonia National Park.