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. 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, called the Twin Ports. It is south of the Iron Range and the Boundary Waters Canoe Area Wilderness. It is named after Daniel Greysolon, Sieur du Lhut, the area's first known European explorer.

Duluth is on the north shore of Lake Superior at the westernmost point of the Great Lakes. It is the largest metropolitan area, the second-largest city, and the largest U.S. city on the lake. Duluth 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 is the largest and busiest port on the Great Lakes. It is also among the top 20 U.S. ports by tonnage. Common items shipped from Duluth include coal, iron ore, grain, limestone, cement, salt, wood pulp, steel coil, and wind turbine parts.

Duluth is a popular Midwest tourist destination. The city is home to the Great Lakes Aquarium, a freshwater aquarium. The Aerial Lift Bridge, next to Canal Park, crosses the Duluth Ship Canal into the Duluth–Superior harbor. Minnesota Point, known locally as Park Point, is the world's longest freshwater baymouth bar, stretching 6 miles (10 km). The city is also the starting point for road trips along the North Shore of Lake Superior to Thunder Bay, Ontario.