It was the residence of the Ruxton family, the owners of this estate and of much of the town property, and was built about the end of the eighteenth century. After the death of the late Mr. William Ruxton in 1896 the family ceased to reside here. His son, Fitzherbert, had been accidentally killed in a polo match in America some years earlier, leaving a widow and son, who remained in Boston.

Mrs. Ruxton's home and the house was let and afterwards sold on the sale of the estate through the Land Commission. Part of the demesne lands were vested by the Land, Commission in trustees for grazing for the townspeople and these also serve as a golf links. A part was made into small holdings and about 70 acres of pasture retained with the ornamental grounds for the house.

When the Louth County Council in 1922 revived the project of withdrawing from the Portrane Asylum Scheme and establishing a Lunatic Asylum for County Louth in Ardee Workhouse buildings it bought Ardee House to replace the Union Hospital. The patients were transferred to it in June 1922, when the Union buildings were needed to accommodate a large party of Belfast refugees. The Hospital has been in operation since and passed under the management of the County Board of Health with the abolition of the Boards of Guardians.