Carmarthenshire is within the Swansea City Sub-Region of the South Wales RAWP area along with Swansea and Neath Port Talbot.
Mae Sir Gaerfyrddin o fewn Is-ranbarth Dinas Abertawe Gweithgor Agregau Rhanbarthol y De ynghyd ag Abertawe a Chastell-nedd Port Talbot.