Mill City Museum is a Minnesota Historical Society museum in Minneapolis. It opened in 2003, built in the ruins of the Washburn "A" Mill next to Mill Ruins Park on the banks of the Mississippi River. It focuses on the founding and growth of Minneapolis, especially flour milling and the other industries which used water power from Saint Anthony Falls.
The mill complex, dating from the 1870s, is listed on the National Register of Historic Places. It is part of the St. Anthony Falls Historic District and within the National Park Service's Mississippi National River and Recreation Area.