Eastern District was one of four districts of the Province of Quebec created in 1788 in the western reaches of the Montreal District and partitioned in 1791 to create the new colony of Upper Canada. Known as Lunenburg District until 1792, it was abolished in 1849. The district seat was in New Johnstown (present day Cornwall, Ontario) .
The district was originally bounded to the west by a line running north from the mouth of the Gananoque River and to the east by Lower Canada. The district town was New Johnstown, later renamed Cornwall. In 1798, the district was reorganized to consist of the counties of: