The house, set high on the South Downs, was built for the first Lord Tankerville c.1690 and subsequently sold to Sir Matthew and Lady Sarah Fetherstonhaugh in 1747. Matthew and Sarah redecorated the house extensively between 1750 - 1760 and introduced most of the exisitng collection of household items displayed today, much of it collected on their Grand Tour in 1749 - 1751. Their only son, Sir Harry Fetherstonhaugh, added to the collection and commissioned Humphry Repton to add a new pillared portico, dairy and landscaped garden. In the 19th century stables and kitchens were added as separate buildings connected to the main building by tunnels.
On 30 August 1989 the building was devastated by a fire caused by a workman's blowtorch whilst repairing lead flashing on the roof, just two days before the work was due to be completed. The fire broke out during opening hours. Many works of art and pieces of furniture were carried out of the burning building by members of the Meade-Fetherstonehaugh family, National Trust staff and members of the public. The fire left nothing but the walls standing, the upper floors collapsing down onto the lower floors.
Most of the pictures and furniture in the house were saved. The building has since been completely restored with many lost crafts relearned in the restoration process, and it re-opened its doors in 1995.
- H.G. Wells spent part of his boyhood at Uppark, where his mother was housekeeper between 1880 - 1893.