Formerly known as Celbridge House, Oakley Park was built in 1742 by Arthur Price, when he was Vicar of Celbridge. The house is attributed to the architect Thomas Burgh, whose descendants still live at Oldtown in Naas. Arthur Price was educated at Trinity College, Dublin, and in later years became its vice-chancellor. In 1730, he was promoted to Bishop of Ferns and in 1734 became Bishop of Meath. While Bishop of Meath he started to build the beautiful Ardbraccan house at Navan as a residence for the Bishops of Meath, although he continued to live at Oakley Park.
During the building of Ardbraccan House, Dr. Arthur Price was promoted Archbishop of Cashel. It is recorded in Ware's antiquities that "it had been much to be wished that he never quitted Meath and then the house at Ardbraccan would have been finished and the noble and venerable Cathedral on the Rock of Cashel would have escaped his destructive hand."
By an Act of Council he "removed" the Cathedral from the Rock of Cashel into the town, uniting it with St. John's Parish. He left the Cathedral on the rock roofless. "By which means that noble and venerable pile has gone to ruin".
At Oakley Park, Dr. Price's steward was Richard Guinness. Part of his duties was to supervise brewing for workers on the estate. Guinness had acquired the reputation of being able to "Make a brew of a very palatable nature." Richard's son, Arthur Guinness, was born in 1725 and was named after Dr. Price, who was his Godfather. In 1759, Arthur Guinness bought a brewery at St. James's gate, Dublin, and started the now world famous Guinness Brewery.
In 1787, George Napier and his wife Lady Saragh Napier took up residence at Oakley Park. Two of Lady Saragh's sisters married into the wealthiest families in the county. Louisa married Thomas Connolly of Castletown, and Emily married James Fitzgerald, Earl of Kildare and first Duke of Leinster.
Lady Emily was mother of the 1798 leader, Lord Edward Fitzgerald.
Colonel Napier sold Oakley Park in 1804 and for the next century the Maunsell family owned the house. In the early years of the 20th century the house had many owners and suffered great neglect.
In 1935, it was purchased by the Guiney family and later sold to the Christian Brothers, who intended to open an industrial school, however, this plan did not materialise. In the early 1950s, Oakley Park was acquired by the St. John of God Brothers, and is now part of the St. Raphael complex.