
Lacon
- County:
- Marshall County
- County Seat:
- Yes
- Area (mi²):
- 1.6
- State:
- Illinois
Lacon is a city located in Marshall County, Illinois. Lacon has a 2025 population of 1,853. It is also the county seat of Marshall County. Lacon is currently declining at a rate of -0.16% annually and its population has decreased by -0.8% since the most recent census, which recorded a population of 1,868 in 2020.
The average household income in Lacon is $75,515 with a poverty rate of 14.32%. The median age in Lacon is 41.4 years: 39.3 years for males, and 44 years for females.