• county
  • FIPS 17075
  • Largest town: Watseka

Iroquois County, Illinois

Iroquois County had 26,067 residents in the Census Vintage 2024 estimate, on 1,117.4 square miles of land. It ranks 51st of 102 in Illinois by population and 3rd by land area.

Population
26,067
#51 of 102 in Illinois · #1,578 in US
Area
1,117.4 sq mi
#3 of 102 in Illinois · #563 in US
Density
23 / sq mi
#85 of 102 in Illinois · #2,119 in US
Median household income
$64,995
#54 of 102 in Illinois · #1,373 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Iroquois County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Iroquois County

Iroquois County population, land area and income

Iroquois County had 26,067 residents in the Census Vintage 2024 estimate, on 1,117.4 square miles of land. It ranks 51st of 102 in Illinois by population and 3rd by land area. That works out to 23.3 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Illinois has 24,447 residents, about the same as Iroquois County.

Its SAIPE 2023 median household income of $64,995 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

26,067

3144th1st

1578th of 3,144 (US)

Land area

1,117 sq mi

3144th1st

563rd of 3,144 (US)

Density

23.3 / sq mi

3144th1st

2119th of 3,144 (US)

Median household income

$64,995

3143rd1st

1373rd of 3,143 (US)

Rank within Illinois (102)

Population

26,067

102nd1st

51st of 102 (IL)

Land area

1,117 sq mi

102nd1st

3rd of 102 (IL)

Density

23.3 / sq mi

102nd1st

85th of 102 (IL)

Median household income

$64,995

102nd1st

54th of 102 (IL)

How Iroquois County's population changed since 2020

Iroquois County lost 899 residents between the July 2020 and July 2024 estimates, a drop of 3.3%. That ranks 88th of 102 in Illinois for growth. The median Illinois county changed by -1.7%, and the state as a whole by -0.7%.

Since the April 2020 estimates base, Iroquois County recorded 1,087 births and 1,837 deaths, a natural change of -750. Net international migration added +29 and net domestic migration, people moving to or from other US counties, came to -279. The largest single component was natural change, which removed 750 people.

27.0k202026.8k202126.4k202226.0k202326.1k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
1,087
Deaths
1,837
Net international migration
+29
Net domestic migration
-279
Change, July 2023 to July 2024
+34

Where Iroquois County is

The Census internal point of Iroquois County is at 40.748900, -87.833600. It sits in UTM zone 16N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Iroquois County outlined. Dots are towns of 1,000+ people with residents in it.

Piatt County: -0.3%Hamilton County: -2.2%Williamson County: -0.1%Edgar County: -2.4%Macoupin County: -2.3%Marshall County: -1.3%Putnam County: +0.0%Richland County: -2.8%Washington County: -1.4%Lee County: -1.5%Douglas County: +0.2%Cook County: -1.6%Effingham County: -0.3%Edwards County: -3.6%Cass County: -2.0%Clay County: -3.4%Knox County: -2.2%LaSalle County: -0.9%Cumberland County: -1.3%Warren County: -3.7%Moultrie County: -0.9%Menard County: -2.5%Fayette County: -1.5%Boone County: -0.0%Lawrence County: -3.2%Marion County: -3.2%Champaign County: +3.0%Clark County: -2.4%Ford County: -0.4%Wayne County: -1.4%Logan County: -1.4%Grundy County: +2.5%Jasper County: -1.8%Crawford County: -1.3%McDonough County: -1.7%Clinton County: +0.5%Perry County: -3.0%Montgomery County: -2.2%Henry County: -2.0%Livingston County: -1.2%Scott County: -3.8%Alexander County: -11.2%Bureau County: -2.2%Brown County: +1.1%Mason County: -3.9%Calhoun County: -4.1%Greene County: -4.3%Coles County: -1.4%Kendall County: +8.2%Lake County: +0.7%Mercer County: -2.2%St. Clair County: -2.3%Wabash County: -3.0%Bond County: -1.7%DuPage County: +0.6%Gallatin County: -5.2%Stephenson County: -3.3%McHenry County: +1.9%White County: -3.0%Saline County: -3.9%Christian County: -2.2%Sangamon County: -1.0%Massac County: -3.6%Macon County: -2.9%Johnson County: -0.0%Jo Daviess County: -2.6%Peoria County: -1.0%DeKalb County: +1.0%Pope County: -1.5%De Witt County: -0.9%Schuyler County: -1.7%Fulton County: -3.1%Ogle County: -0.8%Jersey County: -1.6%Iroquois County: -3.3%Kankakee County: -0.9%Rock Island County: -1.1%Pulaski County: -5.8%Kane County: +0.9%Union County: -2.4%Whiteside County: -1.7%Woodford County: -0.3%Carroll County: -1.5%Adams County: -2.3%Hardin County: -2.6%Madison County: -1.0%Hancock County: -3.1%Monroe County: +0.0%Tazewell County: -1.1%Jackson County: -0.1%Vermilion County: -3.9%Randolph County: -0.6%McLean County: +0.5%Morgan County: -2.6%Shelby County: -1.7%Will County: +1.7%Winnebago County: -0.4%Jefferson County: -2.4%Stark County: -2.2%Henderson County: -4.5%Pike County: -2.6%Franklin County: -1.8%
Change 2020 to 2024
  1. < -3.0%
  2. < -2.2%
  3. < -1.4%
  4. < -0.3%
  5. ≥ -0.3%
no data

Orange pin: Iroquois County internal point. Dark pin: Springfield.

Internal point

Decimal
40.748900, -87.833600
DMS
40°44'56.04"N 87°50'0.96"W
UTM
16N 429627.2E 4511217.4N
Geohash
dp1xc61e8
Plus code
86GJP5X8+HH

Towns in Iroquois County

6 incorporated places of 1,000+ people have residents in Iroquois County, 10,495 people together, or 40% of the county. Each figure counts only the part of the town inside Iroquois County; towns marked "part" extend into another county. The largest is Watseka with 4,495.

  1. 01Watseka4,495
  2. 02Gilman1,674
  3. 03Clifton1,295
  4. 04Onarga1,294
  5. 05Milford1,111
  6. 06Chebanse (part)626
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Iroquois County

The Census 2024 county adjacency file lists 5 neighbors for Iroquois County, including 2 across a state line. The most populous is Kankakee County, IL, with 106,410 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 116.8 miles SW of Iroquois County's internal point in a straight line. The nearest place of 100,000 or more is Joliet, IL (population 151,837), 55.6 miles away. The nearest place of 10,000 or more is Kankakee, IL (population 23,535), 24.4 miles away.

Iroquois County FIPS code

The FIPS code of Iroquois County is 17075: state code 17 for Illinois plus county code 075. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $64,995.

Questions people ask

What is the population of Iroquois County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 26,067. That is down 899 people (3.3%) from the July 2020 estimate of 26,966.

What is the FIPS code of Iroquois County?

17075. The first two digits (17) are Illinois; the last three (075) identify the county.

What is the largest town in Iroquois County?

Watseka, with 4,495 residents inside Iroquois County in 2024.

Which counties border Iroquois County?

5 county-equivalents border it in the Census 2024 adjacency file: Kankakee County, IL; Vermilion County, IL; Newton County, IN; Ford County, IL; Benton County, IN.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.