Llandeilo is a town and community in Carmarthenshire, Wales, situated at the crossing of the River Towy by the A483 on a 19th-century stone bridge. Its population was 1,795 at the 2011 Census. It is adjacent to the westernmost point of the Brecon Beacons National Park. The town is served by Llandeilo railway station on the Heart of Wales Line.

Llandeilo railway station serves the town of Llandeilo, Carmarthenshire. The station is 30+3⁄4 miles (49 km) north east of Swansea on the Heart of Wales Line.