Balloch Castle is an early 19th-century country house situated at the southern tip of Loch Lomond, in West Dunbartonshire, Scotland. Balloch was a property of the Lennox family from the 11th century, and the old castle was built in the 13th century. In the 19th century the estate was purchased by John Buchanan of Ardoch, who demolished the ruins of the old castle and erected the present building. The Tudor Gothic architecture is the work of Robert Lugar. In 1915 Balloch was bought by Glasgow City Corporation, and has been leased by West Dunbartonshire Council since 1975. The estate was designated as a country park in 1980, and since 2002 has been part of Loch Lomond and The Trossachs National Park. Although the house has been periodically used for visitor facilities and council offices, it is now included on the Buildings at Risk Register.