Duluth ⁱ/dəˈluːθ/ is a major port city in the U.S. state of Minnesota and the county seat of Saint Louis County. Duluth has a population of 86,110 and is the second-largest city on Lake Superior's shores, after Thunder Bay, Ontario, in Canada; it has the largest metropolitan area on the lake. The Duluth MSA had a population of 279,771 in 2010, the second-largest in Minnesota.

Situated on the north shore of Lake Superior at the westernmost point of the Great Lakes, Duluth is accessible to oceangoing vessels from the Atlantic Ocean 2,300 miles (3,700 km) away via the Great Lakes Waterway and the Saint Lawrence Seaway.

Duluth forms a metropolitan area with neighboring Superior, Wisconsin, called the Twin Ports. The cities share the Duluth–Superior harbor and together are the Great Lakes' largest port, transporting coal, iron ore (taconite), and grain.