Located 6 miles (10 km) northwest of Ellon in Aberdeenshire, Haddo House was built on the site of an older house between 1732 and 1735 by the architect William Adam (1689 - 1748) for William Gordon (1679 - 1746), 2nd Earl of Aberdeen. It lies amidst a sizeable estate. George Hamilton Gordon (1784 - 1860), the 4th Earl and Prime Minister, significantly enlarged the house and landscaped the estate. James Hamilton Gordon (1847 - 1934), 1st Marquis and 7th Earl, was Laird for 64 years, and together with his formidable wife, Ishbel Marjoribanks, developed Haddo into a model estate greatly benefiting the local community. The pair, collectively referring to themselves as 'We Twa', converted lofts into public rooms, extended the accommodation and installed a beautiful Gothic chapel. This work, together with their philanthropy, had a significant effect on their financial status and thousands of acres of the estate had to be sold off to meet the bills.
Haddo House, used as a maternity hospital during World War II, was acquired by the National Trust for Scotland in 1978 and opened to the public a year later. The adjacent Country Park, run by Aberdeenshire Council, was also opened in 1979.