Llanystumdwy is small village on the Lleyn Peninsula in north Wales. It is located on the A497 between Criccieth in the east and Pwllheli in the west.

It is most notable as the village where David Lloyd George, one of the better known British Prime Ministers lived as a boy. His grave is located in woodland on the outskirts of the village. There is also a museum of Lloyd George memorabilia in the village.