| Duncan Church | |
| Nearest City: | Gann Valley, South Dakota |
| Coordinates: | 44.1805°N -99.0571°W |
| Built: | 1927 |
| Added: | February 12, 1999 |
| Area: | 2.4acres |
| Refnum: | 99000207 |
Duncan Church, also known as Saint Placidus Catholic Church, is a historic church near Gann Valley, South Dakota. It is located southwest of Crow Creek, about 2miles south of the county line. It is about 13miles north and west of Gann Valley. It was built in 1927 and was added to the National Register in 1999.
It is a basilica plan church about NaNfeet in size. It has clapboard siding and a gable roof.[1]