Barry Castle (Welsh: Castell y Barri) is a small Grade II* listed ruined two-storey gatehouse with the adjacent walls of a hall located in the Romilly district of Barry, Vale of Glamorgan in south Wales. The Norman castle was really little more than a small fortified manor house, the seat of the de Barry family, which was built in the 13th and 14th centuries to replace an earlier earthwork.
By the late 13th century the castle had two stone buildings on the east and west sides of a courtyard, but nothing now remains of these above ground. Early in the 14th century the castle was strengthened by the addition of a large hall and gatehouse on its south side, and the ruins of these can be seen today.
The gatehouse passage is arched, with a portcullis groove on the east side. As well as a portcullis it had a drawbridge and double doors. A small room above, whose outer wall and arched window have survived, held the portcullis windlass and possibly a chapel. Behind the gate passage is a rectangular room with a blocked staircase on the southeast corner and an arrowslit on the east wall. The walls of the hall block to the west are much lower, with a low arched doorway and an arrowslit on the north side.
The main hall was located on the first floor, and was heated by a fireplace on the north wall. There was a narrow mural stair in the southeast corner on to a wall-walk on the curtain wall, and a door, the bottom part of which is visible, in the east was leading to the portcullis chamber. There is evidence that the hall was roofed with slate from Cornwall, and had green glazed ridge tiles.