Carmarthen Bay (Welsh: Bae Caerfyrddin) is an inlet of the south Wales coast. The coastline includes notable beaches such as Pendine Sands and Cefn Sidan sands, and is partially within the Pembrokeshire Coast National Park. Wind turbines were tested here in the 1980s. Carmarthen Bay and Estuaries is listed as a Special Area of Conservation by the Joint Nature Conservation Committee
The River Loughor flows into the bay at the Loughor Estuary, and the rivers Towy, Taf and Gwendraeth flow into the bay at the Three Rivers Estuary. Caldey Island lies in the bay near Tenby. Towns and villages in the bay include from east to west, Llanellii, Burry Port, Pembrey, Kidwelly, Ferryside, Llansteffan, Laugharne, Pendine, Amroth, Wisemans Bridge, Saundersfoot and Tenby. There are fine beaches at Pendine Sands, Cefn Sidan, Laugharne, Llansteffan and Ferryside. 
Carmarthen Bay and Estuaries is listed as a Special Area of Conservation by the Joint Nature Conservation Committee, a public body that advises the Welsh Government on international nature conservation. The area conserved includes sea inlets, tidal rivers, estuaries, mud flats, sand flats, lagoons (including saltwork basins), salt marshes, salt pastures, salt steppes, shingle, sea cliffs and islets. The sand and mud flats have large numbers of bivalve molluscs including the edible cockle. The large shallow inlets and bays provide habitat for a great variety of marine invertebrates. The saltmarshes have biodiverse communities of glasswort (Salicornis species), dwarf eelgrass (Zostera noltei), sea rush (Juncus maritimus) and marsh-mallow (Althaea officinalis) and all the wildlife they support. A primary reason for the listing is the presence in the bay of the twait shad (Alosa fallax), a migratory fish.
An area of the Carmarthen Bay coastline near Burry Port was used in the 1980s to test wind turbines. The first turbine to be installed in the area was switched on in November 1982. Five turbines of different designs were tested at the site, installed between 1982 and 1989. The project was concluded in the late 1990s, the turbines were removed, and the land was eventually integrated into the Millennium Coastal Park.
|Wikimedia Commons has media related to Carmarthen Bay.|
- "Landranger 159: Swansea & Gower". 1.25 inch map. Ordnance Survey.
- "Beaches of Carmarthenshire". Discovering Carmarthenshire. Carmarthenshire County Council. Retrieved 27 April 2016.
- "Carmarthen Bay and Estuaries/ Bae Caerfyrddin ac Aberoedd". Joint Nature Conservation Committee. Retrieved 27 April 2016.
- Price, Trevor (2006). "UK Large-Scale Wind Power Programme From 1970 to 1990: The Carmarthen Bay Experiments and the Musgrove Vertical-Axis Turbines" (PDF). Retrieved 2008-12-30.