Cynheidre is a hamlet in the Gwendraeth Fawr valley, in the county of Carmarthenshire, South Wales. It straddles the B4309 road and lies south west of the town Pontyberem, north of Fiveroads and east of Kidwelly. Nearby towns and villages include Pont-Henri, Pontyates, Carway, Trimsaran and Bancffosfelen.
The village has a pleasant children's playground on the edge of the village and the Bryn Seion Chapel on the High Street.
Cynheidre was once home to the Cynheidre Colliery which is now closed and as with much of the Welsh mines is undergoing a successful greening over of the mining scars.
Mynydd Sylen (284m) is just under 5km to the north east of the village Cynheidre. There is a footpath close by that goes up the mountain.
Cyclists will appreciate the major cycle route that weaves its way through Cynheidre en-route from Carmarthen to the Gower Peninsula.