
Williamson
- County:
- Macoupin County
- County Seat:
- No
- Area (mi²):
- 1.171
- State:
- Illinois
Williamson is a village located in Macoupin County, Illinois. Williamson has a 2025 population of 174. Williamson is currently declining at a rate of -0.57% annually and its population has decreased by -3.87% since the most recent census, which recorded a population of 181 in 2020.
The average household income in Williamson is $62,997 with a poverty rate of 17.09%. The median age in Williamson is 55 years: 54.5 years for males, and 60.1 years for females.