The county is bounded to the north by the Irish Sea, to the east by Denbighshire, to the south by Cardigan Bay and Merionethshire, and to the west by Caernarfon Bay and the Menai Strait, separating it from Anglesey.
The principal towns of the county are Bangor, Betws-y-Coed, Caernarfon, Conwy, Llandudno, Porthmadog and Pwllheli.