Llanfynydd is a village in the county of Carmarthenshire in South Wales. The village is situated north west of Llandeilo, north east of Nantgaredig and to the south east of Brechfa.

The village nestles below the steep slopes that form the valley of the Afon Sannan. The river divides and runs to the east and west of the village.

The area holds an assortment of archaeological remains providing evidence of early prehistoric activity and indeed a hill nearby is known as Banc y rhyfel (War Bank) from when Iron Age man chose the hill for his stronghold. Carreg Castell y Gwynt (Windy Rock) is another of the many ancient monuments in the area. The rock is believed to form the stone of a chambered tomb dating back to the Neolithic or Bronze Age times.

The recently renovated Llanfynydd Church is a prominent feature in the village and it's southern divisions date back to the 13th Century, while the northern parts of the church were added in the 15th Century.

Lying 4 miles from Llandeilo and to the south east of Llanfynydd is Capel Isaac (Isaac Chapel). Capel Isaac was built in 1790 and again in 1848, it was one of the first Anabaptist churches in the whole of Wales.