Llanfyllin is a market town, community and electoral ward in a sparsely populated area in Montgomeryshire, Powys, Wales. Llanfyllin's community population in 2011 was 1,532, of whom 34.1% could speak Welsh. Llanfyllin means church or parish of St Myllin. The community includes the tiny settlements of Bodfach, Ty Crwyn, Abernaint and several farms.