The Rush–Bagot Treaty or Rush–Bagot Disarmament was a treaty between the United States and Great Britain limiting naval armaments on the Great Lakes and Lake Champlain, following the War of 1812. It was ratified by the United States Senate on April 16, 1818, and was confirmed by Canada, following Confederation in 1867.
The treaty provided for a large demilitarization of lakes along the international boundary, where many British naval arrangements and forts remained. The treaty stipulated that the United States and British North America could each maintain one military vessel (no more than 100 tons burden) as well as one cannon (no more than eighteen pounds) on Lake Ontario and Lake Champlain.