Trawsfynydd is a linear village in Gwynedd, Wales, near Llyn Trawsfynydd reservoir, and adjacent to the A470 north of Bronaber and Dolgellau and 10 km south of Blaenau Ffestiniog. It also neighbours the towns of Porthmadog and Bala.

Gwynedd is a county in the north-west of Wales. It borders Anglesey across the Menai Strait to the north, Conwy, Denbighshire, and Powys to the east, Ceredigion over the Dyfi estuary to the south, and the Irish Sea to the west. The city of Bangor is the largest settlement, and the administrative centre is Caernarfon. The preserved county of Gwynedd, which is used for ceremonial purposes, includes the Isle of Anglesey.