Piatt County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 62nd-largest in Illinois
The population of Piatt County, Illinois is 16,702 as of the 2023 American Community Survey, making it the 62nd-largest county in Illinois. The median household income is $87,516, the median home value is $173,200, and the median age is 42.5.
The population of Piatt County has declined 0.5% since 2010 (16,710 → 16,628), a -0.04% annualized rate.
16,702
Population
-0.04%
Annual growth
38
People / sq mi
$87,516
Median Income
$173,200
Median Home Value
Piatt County covers 439 sq mi of land at 38.0 people per square mile.
About Piatt County, IL
Piatt County is a county in Illinois with a population of 16,702. It ranks #62 among counties in Illinois by population. The median age is 42.5, older than the national median. The population is 49.6% male and 50.4% female.
The median household income in Piatt County is $87,516, above the US median of $74,580. 4.6% of residents live below the federal poverty level. Home values sit at a median of $173,200, with monthly rent averaging $950. The homeownership rate of 85.4% is higher than the national rate of 64.8%.
Educational attainment in Piatt County reflects 31.9% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 6.9% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 23.7 minutes each way.
Piatt County Population History (2010-2024)
The county of Piatt County had a population of 16,710 in 2010 and 16,628 in 2024, a -0.5% growth over 14 years. The peak was 16,764 in 2021. Average annual growth rate: -0.03%.
16,628
Population (2024)
16,710
Population (2010)
16,764
Peak (2021)
-0.03%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 16,710 |
| 2011 | 16,683 |
| 2012 | 16,505 |
| 2013 | 16,437 |
| 2014 | 16,414 |
| 2015 | 16,356 |
| 2016 | 16,511 |
| 2017 | 16,427 |
| 2018 | 16,375 |
| 2019 | 16,391 |
| 2020 | 16,683 |
| 2021 | 16,764 |
| 2022 | 16,678 |
| 2023 | 16,720 |
| 2024 | 16,628 |
Race & Ethnicity
| White | 95.6% |
| Black or African American | 1.6% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 0.7% |
| Two or More Races | 0.0% |
Age & Sex
42.5
Median Age
50.4%
Female
49.6%
Male
20.5%
Age 65+
Age Distribution
Children (under 15): 18.0% · Seniors (65+): 20.5%
Income & Poverty
| Median household income | $87,516+$5,814 vs state |
| Mean household income | $106,362 |
| Per-capita income | $43,547 |
| Poverty rate | 4.6%-3.6% vs state |
| Unemployment rate | 2.2% |
| Employment-to-population | 62.5% |
Top Industries by Employment
The largest employment sector in Piatt County is professional & business services, accounting for 30.7% of workers.
How residents commute
0.3%
Drive alone
1.5%
Carpool
85.1%
Public transit
6.9%
Work from home
23.7 min
Avg commute
Housing
$173,200$-77,300 vs state
Median home value
$950
Median rent
85.4%
Homeownership rate
7,380
Total housing units
92.8%
Occupied
7.2%
Vacant
14.6%
Renter-occupied
Social & access
97.0%
With health insurance
94.6%
With broadband internet
15.2%
Foreign-born
6.1%
Veterans (18+)
12.1%
With a disability
97.8%
Speak language other than English at home
Education
96.0%
High School+
31.9%
Bachelor's+
Largest cities in Illinois
Other counties in Illinois
Part of Illinois
Metro areas in Illinois
County rankings
Frequently Asked Questions
Piatt County, Illinois has a population of 16,702 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 62nd-largest county in Illinois. Population density is 38 people per square mile.
The population of Piatt County has declined 0.5% since 2010 (16,710 → 16,628), a -0.04% annualized rate.
The median household income in Piatt County, Illinois is $87,516, with mean (average) household income of $106,362 and per-capita income of $43,547. 4.6% of residents live below the federal poverty level.
In Piatt County, the largest racial and ethnic groups are White (95.6%), Black or African American (1.6%), Hispanic or Latino (0.7%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Piatt County, Illinois is 42.5 years. Residents are 50.4% female and 49.6% male.
The median home value in Piatt County is $173,200 and median monthly rent is $950. 85.4% of occupied housing units are owner-occupied. The county has 7,380 total housing units, 7.2% of which are vacant.
The largest employment sector in Piatt County, Illinois is professional, scientific, and management services, employing 30.7% of workers. The unemployment rate is 2.2%.
Chicago is among the largest cities associated with Piatt County, Illinois, with a population of 2,707,648.
More from Illinois
Population 5,185,812
Population 927,263
Population 711,885
Population 698,450
Full rankings of Illinois counties
Statewide data for Illinois
Population, race, income, age, and trends across Illinois
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.