Dundurn Castle is an historic chateau in Hamilton, Ontario, Canada.

Sir Allan MacNab, later prime minister of the united Province of Canada between 1845 and 1856, hired architect Robert Wetherall and consturction of this stately home was completed in 1835. It became the property of the City of Hamilton, and in the late 1960s, it was restored as a Centennial project. It is now designated as a National Historic Site.

It operates as a civic musuem, and its grounds house other atractions. Dundurn Park, and asscoiated green spaces, is a favourite for wedding portraits. The Hamilton Military Museum is housed in an outbuilding which was relocated when York Street was widened as York Boulevard in the 1970s. Another outbuilding, the Cockpit Theatre, occasionally housed outdoor events and dramas.

A large German artillery piece, booty from the First World War, was removed from the southeastern part of the park in the mid-1980s. Until about 1990, it housed an aviary which was moved to the Westdale neighbourhood. The former covered pavillion offered picnickers protection from the cold, but in the last few years a walled garden was put in its place.

See also List of castles.