| Round Barn, Millville Township | |
| Coordinates: | 42.7156°N -91.0844°W |
| Built: | 1916 |
| Architect: | Xavier Jacque |
| Added: | June 30, 1986 |
| Refnum: | 86001423 |
The Round Barn, Millville Township is an historical building located in rural Clayton County, Iowa, United States. It was built in 1916 as a general purpose barn. The building is a true round barn that measures 72feet in diameter.[1] It is covered in metal vertical siding and features a dome roof, a cupola with an aerator and a central silo.[2] It is one of three round barns extant in Iowa known to have a dome roof.[1] The barn has been listed on the National Register of Historic Places since 1986.