Farmleigh (Irish: Bán na Feirme) was formerly one of the Dublin residences of the Guinness family. It is situated in the civil parish of Castleknock on an elevated position above the River Liffey to the north-west of the Phoenix Park. The estate of 78 acres (32 ha) consists of extensive private gardens with stands of mature cypress, pine and oak trees, a boating pond, walled garden, sunken garden, out offices and a herd of rare native Kerry cattle. It was purchased from the 4th Earl of Iveagh in 1999 for €29.2 million. A state body-the Office of Public Works (OPW)-spent in the region of €23 million restoring the house, gardens and curvilinear glasshouses, bringing the total cost to the state to €52.2 million. Farmleigh was opened to the public in July 2001. It is now the official Irish State Guest House.

Farmleigh was once a small Georgian house built in the 18th century. It was purchased by Edward Cecil Guinness when he married his cousin Adelaide Guinness in 1873. He was a great-grandson of Arthur Guinness and was created Baron Iveagh in 1891 and Earl of Iveagh in 1919. A major renovation programme took place between 1881 and 1884 that extended the house to the west and added a third floor designed by Irish architect James Franklin Fuller. A ballroom was added in 1896, designed by the Scottish architect William Young. The conservatory was added in 1901.

Visitors to Farmleigh gain some insight into the character of Edward Cecil Guinness, 1st Lord Iveagh, from the landscaped gardens, the classical architecture, and the symmetrical, sober layout. There are also many tapestries on display, which Guinness collected as historic and unusual textiles while travelling through Europe as a young man. The earls' library, on loan to the state, contains some of the earliest books printed in Ireland.

Current use:

The estate was purchased from the Guinness family by the state in 1999. The official reason for the €29.2 million purchase, and subsequent expenditure of €23 million in refurbishment, was that it would be used for state purposes. Specifically, it is designated as "an official State guest house for visiting heads of State and dignitaries. Some notable visitors have been hosted at Farmleigh including the Chinese Prime Minister, the Prime Minister of Ethiopia, the King of Malaysia, British Prime Minister Tony Blair, and the Governor-General of New Zealand. However, the estate only hosted seven visiting dignitaries in 2006 (the most in one year), six in 2008, and only two the following year. Also in 2009, 246,000 members of the public visited the estate.

Farmleigh has also been used as the venue for the RTÉ proms, a public concert series that takes place each summer in a large marquee erected on the grounds.

In 2006 it was announced by the OPW that the Steward's Lodge which is located in the grounds of Farmleigh had been renovated. It was speculated at the time that the lodge was to become an official residence of the Taoiseach. Former Taoiseach Brian Cowen used the lodge for this purpose on occasion, staying at the lodge while in Dublin. His successor, Enda Kenny, will reportedly become the first full-time resident at the Steward's Lodge.