| Place Name | Duncan Township |
| Place Type | Township |
| ZIP Code(s) | 63556 64630 |
| County | Sullivan County |
| Area Code(s) | 660 |
| Timezone | Central Standard Time (CST) |
| Population (2021) | 279 |
| Majority Ethnicity | White 100% |
| US Congressional District(s) | Missouri 6th |
| State House Districts | 3 |
| State Senate Districts | 12 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 100% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0% |