
Annawan township
- County:
- Henry County
- County Seat:
- No
- Area (mi²):
- 36.318
- State:
- Illinois
Annawan township is located in Henry County, Illinois. Annawan township has a 2025 population of 1,086. Annawan township is currently declining at a rate of -0.46% annually and its population has decreased by -2.86% since the most recent census, which recorded a population of 1,118 in 2020.
The average household income in Annawan township is $91,265 with a poverty rate of 5.35%. The median age in Annawan township is 40.3 years: 35.3 years for males, and 44.8 years for females.