Places beginning with SI in South Dakota, United States
- Sidney, Township of
- Signal, Township of
- Silver City
- Silver Creek, Township of
- Silver Lake (historical), Township of
- Silver Lake, Township of
- Silver Valley Addition
- Sinai
- Sinai, Town of
- Sioux Falls
- Sioux Falls, City of
- Sioux Falls Junction
- Sioux Falls, Township of
- Sioux, Township of
- Sioux Valley, Township of
- Sioux Village
- Sisseton
- Sisseton, City of
- Sisseton, Township of
- Sisseton, Township of
- Sitka