| Place Name | St. Marys Township |
| Place Type | Township |
| ZIP Code(s) | 63662 63673 63673 63775 63781 |
| County | Perry County |
| Area Code(s) | 573 |
| Timezone | Central Standard Time (CST) |
| Population (2021) | 1,661 |
| Majority Ethnicity | White 99.16% |
| US Congressional District(s) | Missouri 8th |
| State House Districts | 145 |
| State Senate Districts | 27 |
| Race/Ethnicy | Percentage of Population (2021) |
|---|---|
| White | 99.16% |
| African American | 0% |
| Hispanic | 0% |
| Asian | 0% |
| Native American | 0% |
| Hawaiin/Pacific Islander | 0.84% |