The Llantwit Major Roman Villa was a Roman L-shaped courtyard villa located at what is now Caermead, immediately north of the town of Llantwit Major in the Welsh county of South Glamorgan.
The villa was first discovered in 1888 and was fully excavated between 1938 and 1948.
The site may have been first settled in the 1st century, but the first stone structure was not erected until a hundred years later. The site developed slowly and, it has been suggested, was even abandoned for a while during the 3rd century. By the 4th century, there was an L-shaped villa with fine mosaic floors, a large aisled building possibly for farm workers and a number of smaller agricultural structures almost enclosing a central courtyard.
No evidence has been found to support the suggestion that the villa was somehow associated with Saint Illtud who founded the church at Llantwit Major in the 6th century.