The Dining Room at Tredegar House was originally known as 'The New Parlour' and was probably used as a private dining room for the family, the Brown Room being used when guests were present. However, during the 19th century, the Brown Room became a sitting room and the New Parlour became the general dining room.

The 17th century panelling was stained, as was the fashion in Victorian times, and the ornate plaster ceiling constructed around 1860, replacing the original.