Erin township
- County:
- Stephenson County
- County Seat:
- No
- Area (mi²):
- 18.148
- State:
- Illinois
Erin township is located in Stephenson County, Illinois. Erin township has a 2026 population of 370. Erin township is currently declining at a rate of -0.54% annually and its population has decreased by -3.14% since the most recent census, which recorded a population of 382 in 2020.
The median household income in Erin township is $84,688 with a poverty rate of 43.74%. The median age in Erin township is 18.9 years: 39.7 years for males, and 17.5 years for females. For every 100 females there are 77.0 males.