Smithville Township is one of six townships within Brunswick County, North Carolina, United States. As of the 2000 Census, Smithville Township had a population of 12,019 and a population density of . It is a part of the Wilmington, NC Metropolitan Statistical Area.
Smithville Township, occupying of land and of water, is located on the Atlantic Ocean coast and encompasses the towns of Oak Island, Southport, Caswell Beach, and Bald Head Island. It is the site of the Brunswick Nuclear Generating Station.