Tremadog Bay
General data
- Name: Tremadog Bay
- Water system: Irish Sea
- Water type: Bay
- Progression: Cardigan Bay -> Irish Sea -> Atlantic Ocean -> Planet Earth
- Climates: Temperate
- Continents: Europe
- Countries: Wales (UK)
Tremadog Bay (also spelled Tremadoc Bay; Welsh: Bae Tremadog), is a shallow inlet of Cardigan Bay in North Wales. It comprises the area between Mochras (Shell Island) in the east and the Trwyn Cilan headland of the Llŷn Peninsula in the west. The Sarn Badrig reef extends south-west from Mochras and forms a natural barrier between Tremadog Bay and Cardigan Bay proper.