Data / Rankings / Foreign-born population share / Counties in Illinois

Counties in Illinois by foreign-born share of the population

Cook County had the highest foreign-born share of the population of 102 counties in 2021, at 20.9%. Clay County had the lowest, at 0.2%. The median was 1.7% and the figure for Illinois was 14.1%. Source: the U.S. Census Bureau.

Highest20.9Cook County
Lowest0.2Clay County
Median1.7102 counties
Illinois14.1History

Top 40 counties, 2021

CSVChart (SVG)

Cook CountyCook County: 20.9 %20.9DuPage CountyDuPage County: 19.6 %19.6Lake CountyLake County: 18.7 %18.7Kane CountyKane County: 17.1 %17.1Champaign CountyChampaign County: 12.4 %12.4Will CountyWill County: 12.4 %12.4Cass CountyCass County: 11.4 %11.4Boone CountyBoone County: 9.3 %9.3Kendall CountyKendall County: 9.3 %9.3Winnebago CountyWinnebago County: 9 %9McHenry CountyMcHenry County: 8.8 %8.8Rock Island CountyRock Island County: 8.2 %8.2DeKalb CountyDeKalb County: 7.1 %7.1McLean CountyMcLean County: 6.9 %6.9Peoria CountyPeoria County: 6.3 %6.3Jackson CountyJackson County: 5.7 %5.7Warren CountyWarren County: 5.7 %5.7Kankakee CountyKankakee County: 4.9 %4.9Grundy CountyGrundy County: 4.1 %4.1Ogle CountyOgle County: 3.7 %3.7Bureau CountyBureau County: 3.6 %3.6LaSalle CountyLaSalle County: 3.3 %3.3Iroquois CountyIroquois County: 3.3 %3.3Knox CountyKnox County: 3.1 %3.1Whiteside CountyWhiteside County: 3.1 %3.1St. Clair CountySt. Clair County: 3.1 %3.1Sangamon CountySangamon County: 3 %3Douglas CountyDouglas County: 3 %3McDonough CountyMcDonough County: 3 %3Brown CountyBrown County: 2.8 %2.8Lee CountyLee County: 2.5 %2.5Randolph CountyRandolph County: 2.5 %2.5Stark CountyStark County: 2.5 %2.5Macon CountyMacon County: 2.4 %2.4Union CountyUnion County: 2.3 %2.3Jo Daviess CountyJo Daviess County: 2.3 %2.3Wabash CountyWabash County: 2.3 %2.3Effingham CountyEffingham County: 2.2 %2.2Carroll CountyCarroll County: 2.2 %2.2Clinton CountyClinton County: 2.2 %2.2
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2021 (%)
1Cook County20.9
2DuPage County19.6
3Lake County18.7
4Kane County17.1
5Champaign County12.4
6Will County12.4
7Cass County11.4
8Boone County9.3
8Kendall County9.3
10Winnebago County9
11McHenry County8.8
12Rock Island County8.2
13DeKalb County7.1
14McLean County6.9
15Peoria County6.3
16Jackson County5.7
17Warren County5.7
18Kankakee County4.9
19Grundy County4.1
20Ogle County3.7
21Bureau County3.6
22LaSalle County3.3
23Iroquois County3.3
24Knox County3.1
25Whiteside County3.1
26St. Clair County3.1
27Sangamon County3
28Douglas County3
29McDonough County3
30Brown County2.8
31Lee County2.5
32Randolph County2.5
32Stark County2.5
34Macon County2.4
35Union County2.3
36Jo Daviess County2.3
37Wabash County2.3
38Effingham County2.2
39Carroll County2.2
39Clinton County2.2
41Vermilion County2.1
42Madison County2.1
43Bond County2
44Williamson County1.9
45Coles County1.9
46Livingston County1.9
47Jefferson County1.9
48Stephenson County1.8
49Woodford County1.7
50De Witt County1.7
51Richland County1.7
52Ford County1.7
53Lawrence County1.7
53Tazewell County1.7
55Hancock County1.6
56Henry County1.6
57Wayne County1.6
58Fayette County1.6
59Montgomery County1.5
60Logan County1.4
61Mercer County1.4
62Marshall County1.4
62Schuyler County1.4
64Putnam County1.4
65Adams County1.3
66Monroe County1.3
67Jasper County1.3
68Christian County1.3
69Menard County1.2
70Perry County1.2
71Crawford County1.2
71Jersey County1.2
73Fulton County1.2
74Scott County1.2
75White County1.1
76Johnson County1.1
77Morgan County1.1
77Washington County1.1
79Massac County1.1
80Cumberland County1.1
81Shelby County1
82Edgar County1
83Pope County1
84Marion County1
85Macoupin County0.9
86Franklin County0.9
86Saline County0.9
88Piatt County0.9
89Pulaski County0.9
90Hamilton County0.8
91Henderson County0.8
92Moultrie County0.8
93Pike County0.8
94Edwards County0.7
95Clark County0.7
96Mason County0.7
97Alexander County0.5
97Hardin County0.5
99Calhoun County0.4
100Greene County0.4
101Gallatin County0.3
102Clay County0.2

Other periods

About this ranking

People who were not US citizens at birth, as a percentage of the total population. Includes naturalized citizens, lawful permanent residents, temporary migrants and unauthorized immigrants. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Based on place of birth, not nationality: a naturalized citizen counts as foreign born, and people born in Puerto Rico, the US island areas or abroad to American parents count as native. Not comparable with foreign_population_share, which counts foreign nationals in Spain and the EU. Calculated from counts in ACS table B05002, which are stored as inputs.

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 B05002: foreign-born population as a percentage of the total population, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b05002.dat. Retrieved 2026-10-09.

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Rank Counties in Illinois by foreign-born share of the population using official data, and cite the source.
rank_places {"indicator":"foreign_born_share","level":"province","within":"Illinois","limit":10}
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Questions

Which county has the highest foreign-born share of the population?

Cook County, with 20.9% in 2021, according to the U.S. Census Bureau.

Which county has the lowest foreign-born share of the population?

Clay County, with 0.2% 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 B05002: foreign-born population as a percentage of the total population, calculated with stored inputs. Retrieved 2026-10-09.

Foreign-born population share: other rankings

Counties in Illinois: more rankings