Data / Rankings / High school graduate or higher, population 25 and over / Counties in Illinois

Counties in Illinois by high school graduate or higher, population 25 and over

McLean County had the highest high school graduate or higher, population 25 and over of 102 counties in 2021, at 96%. Brown County had the lowest, at 80.7%. The median was 90.9% and the figure for Illinois was 89.9%. Source: the U.S. Census Bureau.

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Highest96McLean County
Lowest80.7Brown County
Median90.9102 counties
Illinois89.9History

Map of counties, 2021

Adams County: 92.4 %Alexander County: 86.2 %Bond County: 88.8 %Boone County: 87.1 %Brown County: 80.7 %Bureau County: 90.6 %Calhoun County: 92.8 %Carroll County: 87.9 %Cass County: 84.9 %Champaign County: 94.8 %Christian County: 89.4 %Clark County: 93 %Clay County: 88.4 %Clinton County: 91.3 %Coles County: 91.9 %Cook County: 88 %Crawford County: 86.3 %Cumberland County: 92.9 %DeKalb County: 92.6 %De Witt County: 93.1 %Douglas County: 83.9 %DuPage County: 93.5 %Edgar County: 88 %Edwards County: 92.1 %Effingham County: 93.1 %Fayette County: 86.4 %Ford County: 91.8 %Franklin County: 89.6 %Fulton County: 89.5 %Gallatin County: 88 %Greene County: 90.7 %Grundy County: 93.6 %Hamilton County: 88.2 %Hancock County: 93.4 %Hardin County: 84.8 %Henderson County: 92.5 %Henry County: 92.3 %Iroquois County: 88.4 %Jackson County: 91.6 %Jasper County: 92 %Jefferson County: 89.9 %Jersey County: 92.4 %Jo Daviess County: 92.3 %Johnson County: 83.1 %Kane County: 86 %Kankakee County: 89.5 %Kendall County: 93.6 %Knox County: 88.9 %Lake County: 90.8 %LaSalle County: 90.6 %Lawrence County: 84.4 %Lee County: 89.6 %Livingston County: 90.1 %Logan County: 90.4 %McDonough County: 95.1 %McHenry County: 93.5 %McLean County: 96 %Macon County: 91.8 %Macoupin County: 91.1 %Madison County: 93 %Marion County: 89 %Marshall County: 92.5 %Mason County: 90.6 %Massac County: 87.3 %Menard County: 95.7 %Mercer County: 92.5 %Monroe County: 95.3 %Montgomery County: 87.9 %Morgan County: 89.4 %Moultrie County: 86.6 %Ogle County: 91 %Peoria County: 92.2 %Perry County: 83.6 %Piatt County: 93.7 %Pike County: 91.1 %Pope County: 89.1 %Pulaski County: 89.3 %Putnam County: 93.3 %Randolph County: 85.1 %Richland County: 92.3 %Rock Island County: 89 %St. Clair County: 92.3 %Saline County: 87.9 %Sangamon County: 92.8 %Schuyler County: 92.4 %Scott County: 94 %Shelby County: 93.2 %Stark County: 89.6 %Stephenson County: 91.9 %Tazewell County: 93.2 %Union County: 89.2 %Vermilion County: 90.2 %Wabash County: 91.9 %Warren County: 87.9 %Washington County: 92.1 %Wayne County: 87.4 %White County: 89.7 %Whiteside County: 91.4 %Will County: 91.5 %Williamson County: 92.7 %Winnebago County: 88.2 %Woodford County: 94.3 %
  • Under 88
  • 88 to 89
  • 89 to 91
  • 91 to 92
  • 92 to 93
  • 93 and over
%, 2021. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

McLean County: 96 %McLean County96Menard County: 95.7 %Menard County95.7Monroe County: 95.3 %Monroe County95.3McDonough County: 95.1 %McDonough County95.1Champaign County: 94.8 %Champaign County94.8Woodford County: 94.3 %Woodford County94.3Scott County: 94 %Scott County94Piatt County: 93.7 %Piatt County93.7Kendall County: 93.6 %Kendall County93.6Grundy County: 93.6 %Grundy County93.6McHenry County: 93.5 %McHenry County93.5DuPage County: 93.5 %DuPage County93.5Hancock County: 93.4 %Hancock County93.4Putnam County: 93.3 %Putnam County93.3Tazewell County: 93.2 %Tazewell County93.2Shelby County: 93.2 %Shelby County93.2De Witt County: 93.1 %De Witt County93.1Effingham County: 93.1 %Effingham County93.1Clark County: 93 %Clark County93Madison County: 93 %Madison County93Cumberland County: 92.9 %Cumberland County92.9Sangamon County: 92.8 %Sangamon County92.8Calhoun County: 92.8 %Calhoun County92.8Williamson County: 92.7 %Williamson County92.7DeKalb County: 92.6 %DeKalb County92.6Mercer County: 92.5 %Mercer County92.5Henderson County: 92.5 %Henderson County92.5Marshall County: 92.5 %Marshall County92.5Adams County: 92.4 %Adams County92.4Jersey County: 92.4 %Jersey County92.4Schuyler County: 92.4 %Schuyler County92.4Richland County: 92.3 %Richland County92.3Henry County: 92.3 %Henry County92.3St. Clair County: 92.3 %St. Clair County92.3Jo Daviess County: 92.3 %Jo Daviess County92.3Peoria County: 92.2 %Peoria County92.2Edwards County: 92.1 %Edwards County92.1Washington County: 92.1 %Washington County92.1Jasper County: 92 %Jasper County92Coles County: 91.9 %Coles County91.9McLean County: 96 %McLean County96Menard County: 95.7 %Menard County95.7Monroe County: 95.3 %Monroe County95.3McDonough County: 95.1 %McDonough County95.1Champaign County: 94.8 %Champaign County94.8Woodford County: 94.3 %Woodford County94.3Scott County: 94 %Scott County94Piatt County: 93.7 %Piatt County93.7Kendall County: 93.6 %Kendall County93.6Grundy County: 93.6 %Grundy County93.6McHenry County: 93.5 %McHenry County93.5DuPage County: 93.5 %DuPage County93.5Hancock County: 93.4 %Hancock County93.4Putnam County: 93.3 %Putnam County93.3Tazewell County: 93.2 %Tazewell County93.2Shelby County: 93.2 %Shelby County93.2De Witt County: 93.1 %De Witt County93.1Effingham County: 93.1 %Effingham County93.1Clark County: 93 %Clark County93Madison County: 93 %Madison County93Cumberland County: 92.9 %Cumberland County92.9Sangamon County: 92.8 %Sangamon County92.8Calhoun County: 92.8 %Calhoun County92.8Williamson County: 92.7 %Williamson County92.7DeKalb County: 92.6 %DeKalb County92.6Mercer County: 92.5 %Mercer County92.5Henderson County: 92.5 %Henderson County92.5Marshall County: 92.5 %Marshall County92.5Adams County: 92.4 %Adams County92.4Jersey County: 92.4 %Jersey County92.4Schuyler County: 92.4 %Schuyler County92.4Richland County: 92.3 %Richland County92.3Henry County: 92.3 %Henry County92.3St. Clair County: 92.3 %St. Clair County92.3Jo Daviess County: 92.3 %Jo Daviess County92.3Peoria County: 92.2 %Peoria County92.2Edwards County: 92.1 %Edwards County92.1Washington County: 92.1 %Washington County92.1Jasper County: 92 %Jasper County92Coles County: 91.9 %Coles County91.9
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2021 (%)
1McLean County96
2Menard County95.7
3Monroe County95.3
4McDonough County95.1
5Champaign County94.8
6Woodford County94.3
7Scott County94
8Piatt County93.7
9Kendall County93.6
10Grundy County93.6
11McHenry County93.5
12DuPage County93.5
13Hancock County93.4
14Putnam County93.3
15Tazewell County93.2
16Shelby County93.2
17De Witt County93.1
17Effingham County93.1
19Clark County93
20Madison County93
21Cumberland County92.9
22Sangamon County92.8
23Calhoun County92.8
24Williamson County92.7
25DeKalb County92.6
26Mercer County92.5
27Henderson County92.5
28Marshall County92.5
29Adams County92.4
30Jersey County92.4
30Schuyler County92.4
32Richland County92.3
33Henry County92.3
34St. Clair County92.3
35Jo Daviess County92.3
36Peoria County92.2
37Edwards County92.1
37Washington County92.1
39Jasper County92
40Coles County91.9
41Stephenson County91.9
42Wabash County91.9
43Ford County91.8
43Macon County91.8
45Jackson County91.6
46Will County91.5
47Whiteside County91.4
48Clinton County91.3
49Pike County91.1
50Macoupin County91.1
51Ogle County91
52Lake County90.8
53Greene County90.7
54Mason County90.6
55Bureau County90.6
56LaSalle County90.6
57Logan County90.4
58Vermilion County90.2
59Livingston County90.1
60Jefferson County89.9
61White County89.7
62Lee County89.6
63Stark County89.6
64Franklin County89.6
65Kankakee County89.5
66Fulton County89.5
67Christian County89.4
67Morgan County89.4
69Pulaski County89.3
70Union County89.2
71Pope County89.1
72Rock Island County89
73Marion County89
74Knox County88.9
75Bond County88.8
76Iroquois County88.4
77Clay County88.4
78Winnebago County88.2
79Hamilton County88.2
80Gallatin County88
81Edgar County88
82Cook County88
83Carroll County87.9
84Warren County87.9
85Montgomery County87.9
85Saline County87.9
87Wayne County87.4
88Massac County87.3
89Boone County87.1
90Moultrie County86.6
91Fayette County86.4
92Crawford County86.3
93Alexander County86.2
94Kane County86
95Randolph County85.1
96Cass County84.9
97Hardin County84.8
98Lawrence County84.4
99Douglas County83.9
100Perry County83.6
101Johnson County83.1
102Brown County80.7

Other periods

About this ranking

People aged 25 and over who hold a regular high school diploma, a GED or alternative credential, or any higher level of education, as a percentage of all people aged 25 and over. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Measures the adult population, not students: it is not the high school graduation rate of a class. Not comparable with the EU share below upper secondary education, which covers ages 25 to 64.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs (Counties in Illinois by high school graduate or higher, population 25 and over, 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat

MLA 9

American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs, Counties in Illinois by high school graduate or higher, population 25 and over, 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. Counties in Illinois by high school graduate or higher, population 25 and over, 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Also distributed by Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021.

Harvard

U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs, Counties in Illinois by high school graduate or higher, population 25 and over, 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat, via Invokely: https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_illinois_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs: Counties in Illinois by high school graduate or higher, population 25 and over, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs: Counties in Illinois by high school graduate or higher, population 25 and over, 2021
PY  - 2026
DA  - 2026/01/29
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat
L2  - https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/illinois-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Retrieved 2026-10-12.
ER  -
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Rank Counties in Illinois by high school graduate or higher, population 25 and over using official data, and cite the source.
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Questions

Which county has the highest high school graduate or higher, population 25 and over?

McLean County, with 96% in 2021, according to the U.S. Census Bureau.

Which county has the lowest high school graduate or higher, population 25 and over?

Brown County, with 80.7% in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. Retrieved 2026-10-12.

High school graduate or higher, population 25 and over: other rankings

Counties in Illinois: more rankings