Monticello Flag

Monticello

County:
Piatt County
County Seat:
Yes
Area (mi²):
3.878
State:
Illinois

Monticello is a city located in Piatt County, Illinois. Monticello has a 2026 population of 6,010. It is also the county seat of Piatt County. Monticello is currently declining at a rate of -0.17% annually but its population has increased by 1.04% since the most recent census, which recorded a population of 5,948 in 2020.

6K
Total Population
1,550
Density (mi²)
-10 -0.17%
Growth

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)