In 1837 Samuel Lewis in his Topographical Dictionary of Ireland described the Castle as follows:
'Mitchelstown Castle, the splendid seat of the Earl of Kingston, is a noble and sumptuous structure of hewn stone, in the castellated style, erected after a design by Mr. Pain, of Cork, at an expense of more than £100,000. The buildings occupy three sides of a quadrangle, the fourth being occupied by a terrace, under which are various offices: the principal entrance, on the eastern range, is flanked by two lofty square towers rising to the height of 106 feet, one of which is called the White Knight's tower, from its being built on the site of the tower of that name which formed part of the old mansion; and at the northern extremity of the same range are two octagonal towers of lofty elevation.
The entrance hall opens into a stately hall or gallery, 80 feet in length, with an elaborately groined roof, richly ornamented with fine tracery, and furnished with elegant stoves of bronze, and with figures of warriors armed cap-a-pie; at the further extremity is the grand staircase. Parallel with the gallery, and forming the south front and principal range, are the dining and drawing-rooms, both noble apartments superbly fitted up and opening into the library, which is between them: the whole pile has a character of stately baronial magnificence, and from its great extent and elevation forms a conspicuous feature in the surrounding scenery. Near the Castle is a large fish-pond, and from a small tower on its margin, water is conveyed to the baths and to the upper apartments of the castle, and across the demesne to the gardens, by machinery of superior construction'.
The Castle was burned down during the Irish Civil War.