Eaton Hall is a large house in King City, Ontario, Canada, built in the Norman style for Lady Eaton in 1938-39 on a 700-acre (2.8 km²) parcel of land (partly the Ferguson farm). Lady Eaton and her husband, Sir John Craig Eaton acquired the land in 1920 and 1922 on recommendation from their friend Sir Henry Pellatt, who owned the nearby Mary Lake property. Lady Eaton moved into Eaton Hall three years after selling 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.
Site plans and surveys for the property dating from 1921 to the 1930s all refer to its location being in Eversley. Design was started in 1932 by architects from the firm of Peter Allward and George Gouinlock. Construction was completed in 1939 and was supervised by John W. Bowser of the Aurora Building Company. Its construction incorporated stones sourced from the nearby Humber River.
Flora Eaton was a member of the Toronto Hunt Club. In 1929, it split into the Eglinton Hunt Club and the Toronto and North York Hunt Club. Hunters of the latter held regular outings, meeting for breakfast at Eaton Hall, riding in the adjacent Pellatt Estate, then ending the day with an afternoon tea at Eaton Hall.
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.