Pencoed Castle is a ruined Tudor mansion, largely dating from the 16th century, in the parish of Llanmartin, now within the city of Newport, south Wales.

The Welsh name Pen-coed means "end of the wood", and refers to the site's location at the southwestern extremity of the Wentwood forest.

[4] In about 1545, John Leland mentioned Pencoed as the home of Sir Thomas Morgan, and described it as "a fair maner place".

[3] Thomas intended to restore the house, and began work on the main central building, but it was incomplete at the time of his death in 1918.

His widow then commissioned Chepstow architect Eric Francis to build a new house adjoining the ruins, in 1922; she sold it a few years later and it is now a farmhouse.

[4] In 1953, at the time of the historic listing, the castle was described as consisting of "a large three storied Tudor manorhouse constructed of dressed stone and re-faced in ashlar to the front (W) elevation, with battlemented parapet".

[8] A 2011 Royal Commission report stated that "restoration work stopped at the outbreak of war, and was resumed by Lady Rhondda and her daughter in 1919 ...

[11] In 1998, further proposals came forward to build a large theme park, billed as the largest in Europe, around the ruins of Pencoed.

[14] In July 2007, planning permission was granted to Morspan Holdings to convert the castle "into offices, and to build 12 houses in the grounds", with certain conditions.

A report at the time stated that in recent years, the castle had been used "as a chicken shed and a shelter for cattle and sheep".

[20] The auction listing said that planning permission had already been obtained for restoration of the castle and for conversion of the outbuildings to offices and dwellings.

The main range is largely intact, rising to three storeys and constructed of ashlar stone, similar to that of Raglan Castle, built around the same time.

Close to the north side of the castle stands a twentieth century house..."[9] The description before sale in 2020 suggested that some restoration had been completed on the property.