Dumfries House is a Palladian country house in Ayrshire, Scotland. It is located within a large estate, around two miles (3 km) west of Cumnock. Noted for being one of the few such houses with much of its original 18th-century furniture still present, including specially commissioned Thomas Chippendale pieces, the house and estate is now owned by The Prince's Foundation, a charity which maintains it as a visitor attraction and hospitality and wedding venue. Both the house and the gardens are listed as significant aspects of Scottish heritage.
The estate and an earlier house were originally called Lefnoreis Castle, owned by a branch of the Craufurds of Loudoun. The present house was built in the 1750s for William Dalrymple, 5th Earl of Dumfries, by John and Robert Adam. Having been inherited by the 2nd Marquess of Bute in 1814, it remained in his family until 2007 when the 7th Marquess sold it.Due to its significance and the risk of the furniture collection being distributed and auctioned, in 2007 the estate and its contents were purchased by a consortium headed by the Prince of Wales, including a £20m loan from the Prince's charitable trust. The intention was to renovate the estate to become self-sufficient, both to preserve it and regenerate the local economy. As well as donors and sponsorship, funding was also intended to come from constructing the nearby housing development of Knockroon, a planned community along the lines of the Prince's similar venture, Poundbury in Dorset.
The house reopened in 2008, equipped for public tours. Since then various other parts of the estate have been reopened for various uses, to provide both education and employment, as well as funding the trust's running costs. The Prince of Wales was in residence at the estate on 8 September 2022, when his mother, Queen Elizabeth II, became gravely ill; he was transported by helicopter to Balmoral Castle, where she died later the same day.