Eaton Hall is a large house in King City, Ontario, Canada, built in the Norman style for Lady Eaton in 1937 on a 700 acre (2.8 km²) parcel of land (once the Fergueson farm). Lady Eaton and her husband, Sir John Craig Eaton acquired the land in 1919 on recommendation from their friend Sir Henry Pellatt, who owned the nearby Mary Lake property. Lady Eaton moved into Eaton Hall following the demolition of her city mansion, Ardwold. The house is adjacent to a body of water named Lake Jonda (a combination of the first three letters of her son John David Eaton's first and middle names), and nestled within the temperate forests of King Township. Upon completion, it contained 72 rooms. It became a beloved gathering place for the Eaton Family, owners of the Eaton's department stores based in Toronto.
Design was started in 1932 by architects from the firm of Peter Allward and George Gouinlock. Construction was completed in 1939 and was carried out by John W. Bowser.
After Lady Eaton's death in 1970, the land was sold to Seneca College, which was then a provincially-funded community college. It established its King Campus operations on that land in 1971, using Eaton Hall as its administrative facility. In 1977, a new facility was built for the expanding college, and Eaton Hall became a Management Development Centre until 1991, at which time it was converted to a public hotel and conference centre.