Llanfihangel-ar-Arth is a village and a community in the county of Carmarthenshire, Wales.
The area includes six villages namely: Alltwalis, Dolgran, Gwyddgrug, Llanfihangel-Ar-Arth, New Inn and Pencader. The population of the community taken at the 2011 census was 2,213.
The village is located around the B4336 between Llanllwni and Llandysul from the east to west and the B4459 between Capel Dewi and Pencader from the north to south.
Llanfihangel ar Arth is the most northerly village in the community, nearest the river Teifi. It is believed that the village’s name derives from the name of the parish church, Sant Mihangel, which was established in the 6th century.
An electoral ward of the same name exists. This ward stretches beyond the community. The total population of this ward taken at the 2011 census was 2,851.
The community is bordered by the communities of: Llanllwni; Llanfihangel Rhos-y-Corn; Llanllawddog; Llanpumsaint; Cynwyl Elfed; and Llangeler, all being in Carmarthenshire; and by Llandysul in Ceredigion.
There was a toll house in the village during 1840–1850 to collect tolls from travellers, and one of the Rebecca Riots occurred here when the gate was destroyed by 150 people in June 1843. It was a one level building and now it is a residential bungalow.