Trefor is a village on the northern coast of the Llŷn Peninsula, in Gwynedd, Wales. It had a population of 1,067 at the 2021 Census. Trefor is in the Community of Llanaelhaearn, and Llithfaen is nearby. There is a beach in Trefor and also a shop in the village centre. It was in the historic county of Caernarfonshire.