Duluth ( də-LOOTH) is a port city in the U.S. state of Minnesota and the county seat of St. Louis County. Located on Lake Superior in Minnesota's Arrowhead Region, the city is a hub for cargo shipping. Commodities shipped from the Port of Duluth include coal, iron ore, grain, limestone, cement, salt, wood pulp, steel coil, and wind turbine components. Duluth is south of the Iron Range and the Boundary Waters Canoe Area Wilderness.

Duluth is named after Daniel Greysolon, Sieur du Lhut, the area's first known European explorer. The population was 86,697 at the 2020 census, making it Minnesota's fifth-largest city. Duluth forms a metropolitan area with neighboring Superior, Wisconsin. The two cities are commonly called the Twin Ports.

Situated on the north shore of Lake Superior at the westernmost point of the Great Lakes, Duluth is the largest metropolitan area, the second-largest city and the largest U.S. city on the lake, and is accessible to the Atlantic Ocean 2,300 miles (3,700 km) away via the Great Lakes Waterway and St. Lawrence Seaway. The Port of Duluth is the world's farthest inland port accessible to oceangoing ships, and by far the largest and busiest port on the Great Lakes. The port is among the top 20 U.S. ports by tonnage.

A tourist destination for the Midwest, Duluth has the nation's only all-freshwater aquarium, the Great Lakes Aquarium; the Aerial Lift Bridge, which is adjacent to Canal Park and spans the Duluth Ship Canal into the Duluth–Superior harbor; and Minnesota Point (known locally as Park Point), the world's longest freshwater baymouth bar, spanning 6 miles (10 km). The city is also the starting point for vehicle trips touring the North Shore of Lake Superior toward Thunder Bay, Ontario, Canada.