New Surprise Valley township
- County:
- Mellette County
- County Seat:
- No
- Area (mi²):
- 35.745
- State:
- South Dakota
New Surprise Valley township is located in Mellette County, South Dakota. New Surprise Valley township has a 2026 population of 6. New Surprise Valley township is currently declining at a rate of 0% annually and its population has decreased by 0% since the most recent census, which recorded a population of 6 in 2020.