Penarth Marina occupies the historic basins of Penarth Docks in the Vale of Glamorgan, South Wales, sitting within the sheltered freshwater impoundment created by the Cardiff Bay Barrage.

It holds a 5 Gold Anchors award from the Yacht Harbour Association and is recognised as Cardiff Bay's premier berthing location for both resident and visiting craft.

Access is via the Cardiff Bay Barrage locks; mariners should contact the marina on VHF Ch80 before arrival. Water levels inside the marina are normally held level with Cardiff Bay, allowing free-flow passage between the two without locking.

Once through the barrage, the marina entrance is immediately to port. The location serves as a practical base for exploring the Bristol Channel and Severn Estuary, with the town of Penarth and central Cardiff both close at hand.