| Official Name: | Foster Township, South Dakota |
| Settlement Type: | Township |
| Pushpin Map: | South Dakota |
| Pushpin Label: | Foster Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | South Dakota |
| Subdivision Type2: | County |
| Subdivision Name2: | Perkins |
| Area Total Sq Mi: | 64.3 |
| Population As Of: | 2020 |
| Population Total: | 11 |
| Population Density Sq Mi: | 0.2 |
| Coordinates: | 45.3464°N -102.1192°W |
Foster Township is a township in Perkins County, in the U.S. state of South Dakota. As of the 2020 census, it contains 11 people and 11 households.[1]