Union township
- County:
- Sanborn County
- County Seat:
- No
- Area (mi²):
- 35.848
- State:
- South Dakota
Union township is located in Sanborn County, South Dakota. Union township has a 2026 population of 57. Union township is currently declining at a rate of -1.72% annually but its population has increased by 3.64% since the most recent census, which recorded a population of 55 in 2020.
The median household income in Union township is $117,083 with a poverty rate of 4.49%. The median age in Union township is 26.3 years: 23.8 years for males, and 26.5 years for females. For every 100 females there are 97.8 males.