Gwyddgrug is a village in Carmarthenshire, Wales.
It is situated within the SA39 postcode district, which is within the Pencader post town.
SA39 is the only postcode district within the Pencader post town.
The Pencader post town is within the Swansea postcode area.
Administrative Ward: Llanfihangel-ar-Arth
Administrative District: Carmarthenshire
Country: Wales
UK Parliament: Carmarthen East and Dinefwr