Penarth is a town and community in the Vale of Glamorgan, Wales, approximately 3 miles (4.8 km) south of Cardiff city centre on the west shore of the Severn Estuary at the southern end of Cardiff Bay.

The Vale of Glamorgan, locally referred to as The Vale, is a county borough in the south-east of Wales. It borders Bridgend County Borough to the west, Cardiff to the east, Rhondda Cynon Taf to the north, and the Bristol Channel to the south. With an economy based largely on agriculture and chemicals, it is the southernmost unitary authority in Wales. Attractions include Barry Island Pleasure Park, the Barry Tourist Railway, Medieval wall paintings in St Cadoc's Church, Llancarfan, Porthkerry Park, St Donat's Castle, Cosmeston Lakes Country Park and Cosmeston Medieval Village. The largest town is Barry. Other towns include Penarth, Llantwit Major, and Cowbridge. There are many villages in the county borough.