Duluth is the county seat of St. Louis County, Minnesota, United States. As of the 2000 census, the city had a total population of 86,918. Taking account of the growth of the city and its boundaries, there are around an extra 92,000 people on the outer-boundaries, making the population (including outer-suburbs and villages) 184,000. It is a seaport at the westernmost point on the north shore of Lake Superior. It is linked to the Atlantic Ocean 2,300 miles (3,700km) away via the Great Lakes and then either the Erie Canal/New York State Barge Canal or the Saint Lawrence Seaway; it is farther from the ocean than any other deep water port. The current mayor of Duluth is Herb Bergson , who is serving his first term. He has announced in June 2006, that he will not be running for re-election to better focus on city issues at hand without the hassle of election campaigning.

Duluth forms a single metropolitan area with Superior, Wisconsin, together called the Twin Ports. The two cities share a harbor and are one of the most important ports on the Great Lakes. Among the items shipped out are iron ore (taconite) and grain. Both cities have museums devoted to the local nautical heritage, and Duluth has America's only all freshwater aquarium, the Great Lakes Aquarium. A major destination for tourists is the Aerial Lift Bridge spanning the short canal into Duluth's harbor. It is a vertical lift bridge, and notable in that it was originally built as an exceedingly rare aerial transfer bridge.

The city is named for Daniel Greysolon, Sieur du Luth, the first known European explorer of the area.

The northern terminus of Interstate 35 is in Duluth. The highway extends south through the state to the Twin Cities, and continues its southerly course to the city of Laredo, Texas.