• county
  • FIPS 17017
  • Largest town: Beardstown

Cass County, Illinois

Cass County had 12,713 residents in the Census Vintage 2024 estimate, on 375.8 square miles of land. It ranks 81st of 102 in Illinois by population and 79th by land area.

Population
12,713
#81 of 102 in Illinois · #2,240 in US
Area
375.8 sq mi
#79 of 102 in Illinois · #2,618 in US
Density
34 / sq mi
#70 of 102 in Illinois · #1,823 in US
Median household income
$64,413
#61 of 102 in Illinois · #1,422 in US

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

Cass County within Illinois. Pin: Springfield.

Measure from here

Tools and pages that start from Cass County

Cass County population, land area and income

Cass County had 12,713 residents in the Census Vintage 2024 estimate, on 375.8 square miles of land. It ranks 81st of 102 in Illinois by population and 79th by land area. That works out to 33.8 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; Cass County is somewhat smaller.

Its SAIPE 2023 median household income of $64,413 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

12,713

3144th1st

2240th of 3,144 (US)

Land area

376 sq mi

3144th1st

2618th of 3,144 (US)

Density

33.8 / sq mi

3144th1st

1823rd of 3,144 (US)

Median household income

$64,413

3143rd1st

1422nd of 3,143 (US)

Rank within Illinois (102)

Population

12,713

102nd1st

81st of 102 (IL)

Land area

376 sq mi

102nd1st

79th of 102 (IL)

Density

33.8 / sq mi

102nd1st

70th of 102 (IL)

Median household income

$64,413

102nd1st

61st of 102 (IL)

How Cass County's population changed since 2020

Cass County lost 263 residents between the July 2020 and July 2024 estimates, a drop of 2.0%. That ranks 57th 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, Cass County recorded 690 births and 588 deaths, a natural change of +102. Net international migration added +566 and net domestic migration, people moving to or from other US counties, came to -980. The largest single component was domestic migration, which removed 980 people.

13.0k202012.8k202112.7k202212.8k202312.7k2024
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
690
Deaths
588
Net international migration
+566
Net domestic migration
-980
Change, July 2023 to July 2024
-66

Where Cass County is

The Census internal point of Cass County is at 39.969200, -90.245700. It sits in UTM zone 15N. The map shades Illinois's 102 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Cass 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: Cass County internal point. Dark pin: Springfield.

Internal point

Decimal
39.969200, -90.245700
DMS
39°58'9.12"N 90°14'44.52"W
UTM
15N 735227.8E 4427972.2N
Geohash
9zpg6kjj6
Plus code
86FFXQ93+MP

Towns in Cass County

3 incorporated places of 1,000+ people have residents in Cass County, 8,461 people together, or 67% of the county. Each figure counts only the part of the town inside Cass County; towns marked "part" extend into another county. The largest is Beardstown with 5,803.

  1. 01Beardstown5,803
  2. 02Virginia1,470
  3. 03Ashland1,188
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Cass County

The Census 2024 county adjacency file lists 6 neighbors for Cass County. The most populous is Sangamon County, IL, with 194,345 residents. Distances run between Census internal points in a straight line.

Distance to Springfield and the nearest big city

Springfield is 34.2 miles ESE of Cass County's internal point in a straight line. The nearest place of 100,000 or more is Springfield, IL (population 112,949), 34.2 miles away. The nearest place of 10,000 or more is Jacksonville, IL (population 17,801), 16.6 miles away.

Cass County FIPS code

The FIPS code of Cass County is 17017: state code 17 for Illinois plus county code 017. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $64,413.

Questions people ask

What is the population of Cass County, Illinois?

The Census Vintage 2024 estimate for July 1, 2024 is 12,713. That is down 263 people (2.0%) from the July 2020 estimate of 12,976.

What is the FIPS code of Cass County?

17017. The first two digits (17) are Illinois; the last three (017) identify the county.

What is the largest town in Cass County?

Beardstown, with 5,803 residents inside Cass County in 2024.

Which counties border Cass County?

6 county-equivalents border it in the Census 2024 adjacency file: Sangamon County, IL; Morgan County, IL; Mason County, IL; Menard County, IL; Schuyler County, IL; Brown County, IL.

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.