
South Flannigan township
- County:
- Hamilton County
- County Seat:
- No
- Area (mi²):
- 18.34
- State:
- Illinois
South Flannigan township is located in Hamilton County, Illinois. South Flannigan township has a 2025 population of 134. South Flannigan township is currently declining at a rate of -1.47% annually and its population has decreased by -4.29% since the most recent census, which recorded a population of 140 in 2020.
The average household income in South Flannigan township is $104,887 with a poverty rate of 4.76%. The median age in South Flannigan township is 33.3 years: 22.9 years for males, and 33.7 years for females.