Llyn Fanod is an upland lake situated between Penuwch and Bontnewydd in Ceredigion, Wales. It is a Site of Special Scientific Interest partly owned by the Wildlife Trust of South and West Wales. Public access is via a bridlepath from the road. It is a mesotrophic lake located in the headwaters of the River Aeron, whose low nutrient waters are home to a number of locally rare water plants. Waterfowl and passing sea birds can be seen on the lake as can dragonflies in the summer.