The Ceiriog Valley (Welsh: Dyffryn Ceiriog) is the valley of the River Ceiriog in north-east Wales. Its Welsh name, "Dyffryn Ceiriog", is the name of an electoral ward of Wrexham County Borough. The ward is the largest ward of the county borough by area and forms a strikingly-shaped salient of the county borough between Powys and Denbighshire.