Llanfairpwllgwyngyll or Llanfair Pwllgwyngyll is a large village and local government community on the island of Anglesey, Wales, on the Menai Strait next to the Britannia Bridge and across the strait from Bangor. Both shortened and lengthened forms of the placename are used in various contexts.
At the 2011 Census, the population was 3,107, of whom 71% could speak Welsh. It is the sixth largest settlement on the island by population.
The long form of the name, with 58 characters split into 18 syllables, is purported to be the longest place name in Europe and the second longest one-word place name in the world.