Yankton County South Dakota (Historic Districts) has 7 places on the National Register of Historic Places including 2 places of National significance and 3 places of Statewide significance. Significant places include Yankton Historic Commercial District, Yankton Historic Commercial District (Boundary Decrease), Human Services Center, Yankton College Historic District and Yankton Historic District.
Some of the country's most noteable architects helped create the Yankton County places including Sydney Smith, J.H. Coxhead, I.J. Galbraith, Clayton Christopherson, George Elmslie and Dr. Leonard C. Mead. Prominent architectural styles found in Yankton Country are Italianate, Prairie School and Romanesque.