The Delphi Courthouse Square Historic District in Delphi, Indiana is a 23-acre (9.3 ha) area roughly bounded by Monroe, Main, Market and Indiana Streets. It was listed on the National Register of Historic Places in 2010. It includes Italianate architecture and Classical Revival architecture and work by Elmer Dunlap among its 31 contributing buildings.William Wilson donated 100 acres (40 ha) along Deer Creek for the town. The Indian mill sites located along the Creek made this a valuable site.