KILMAINHAM, a suburban village in the parish of St. James, Uppercross barony, Dublin county, two miles W. from the General Post Office, Dublin, comprising an area of 38 acres. Population 670, inhabiting 58 houses. It is situated on the road to Naas, and close to the line of the Cashel or Great Southern and Western Railway.

It is but a poor outlet, interesting only as regards its antiquity. Royal Hospital, County Court House, and Gaol. The name was anciently Kilmaignend, from an abbey or priory founded here by St. Maignend, in the sixth century, and where Strongbow erected a priory of Knights Templars in 1174, which existed until the suppression of that order in 1307, when the then Pope granted it to the Knights of St. John of Jerusalem, who held it until the dissolution of religious houses. All its priors were lords of parliament, and many of them filled high offices, as lord deputy, lord chancellor, &c. On its site is the Royal Hospital of Kilmainham, nearly alike to that of Chelsea, near London, for maimed officers and soldiers, erected in 1680, after a design of Sir Christopher Wren, at an expense of £23,559. It is a quadrangular building, two stories high, enclosing an area 210 feet square, neatly intersected by walks. The north entrance, of the Corinthian order, is surmounted by a square tower, clock turret, and octagonal spire. The dining-hall, 100 feet long, is wainscotted with oak, and ornamented with various military weapons, and portraits of most of the sovereigns and viceroys. The chapel has a very pleasing and venerable appearance, with a beautiful ornamented ceiling, and the east window is considered a relic of the ancient priory. The master of the establishment is generally the Commander of the Forces, who makes this his official residence, from whence, like the Horse Guards, London, all the military organization and arrangements take place as regards Ireland. The Hospital is maintained by an annual parliamentary grant, amounting, for 1846, to £2,599, and provides every necessary comfort for upward of 250 veterans and officers. The County Court House is a large and handsome edifice, connected with which is the County Gaol, a spacious and well arranged prison. The election for the members of the county, its also Quarter Sessions, are held here. In the village there is an Independent Meeting-house. The Hibernian woollen mills of Messrs. Willan give employment to a great number of persons.

To the N. W. of the Royal Hospital, on the Military-road, is the terminus of the Cashel or Great Southern and Western railway. The roof is supported by 72 cast iron columns, underneath which are Six lines of rails, and a platform 612 feet in length. It is within the General Post Office delivery. Letters to be forwarded same day or evening, must be deposited in the Post Office receiver at noon, or by 4, P.m.