Llanfair-yng-Nghornwy (, also spelt Llanfairynghornwy) is a village in Anglesey, in north-west Wales. A sparsely populated parish, it contains two well known geographical features; Carmel Head and, offshore, The Skerries islands with their lighthouse.
Until 1984, Llanfairynghornwy was a community. Today it is part of the community of Cylch-y-Garn.