Johnson County Demographics

A map of Johnson County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	10,716	10,895	80.1%	81.9%
Black	1,039	1,419	7.8%	10.7%
Multiracial	958	388	7.2%	2.9%
Hispanic	597	552	4.5%	4.1%
Asian	33	18	0.2%	0.1%
Native American/Other	33	36	0.2%	0.3%

Johnson County, Illinois has an estimated population of 13,376, a less than 1% change from the 13,308 recorded in the 2020 Census. The population is 80.1% White, 7.8% Black, 7.2% Multiracial, 4.5% Hispanic, 0.2% Asian, and 0.2% Native American/Other. This demographic dot map shows the population of Johnson County, with one dot drawn for each person counted by the Census, color-coded by race.

Johnson has become more racially diverse since the 2020 Census. It is considerably less diverse than Illinois overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In Johnson County, that probability was 31.6% in 2020 and 34.5% in the most recent ACS estimates.

Johnson County is ranked the 79th most populous county in Illinois, out of 102 counties. Johnson County was ranked the 79th most populous county in the 2020 Census.

Johnson County's White Population

10,716 residents of Johnson County, or 80.1% of the population, identify as White. The share of White residents in Johnson County is significantly higher than in Illinois overall, where 58.1% of the population is White. Johnson County ranks 73rd statewide in terms of White residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's White population has declined by an estimated 1.6%. White residents' share of Johnson County's population has decreased from 81.9% to 80.1%.

Johnson County is more White than neighboring Pulaski County (61.9% White). Johnson County is less White than neighboring Williamson County (87.9% White), Massac County (86.3% White), Pope County (88.7% White), and Union County (89.5% White).

Johnson County's Black Population

1,039 residents of Johnson County, or 7.8% of the population, identify as Black. The share of Black residents in Johnson County is lower than in Illinois overall, where 13.3% of the population is Black. Johnson County ranks 16th statewide in terms of Black residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's Black population has declined by an estimated 26.8%. Black residents' share of Johnson County's population has decreased from 10.7% to 7.8%.

Johnson County is more Black than neighboring Williamson County (4.3% Black), Massac County (6.4% Black), Pope County (4.8% Black), and Union County (0.9% Black). Johnson County is less Black than neighboring Pulaski County (33.6% Black).

Johnson County's Asian Population

33 residents of Johnson County, or 0.2% of the population, identify as Asian. The share of Asian residents in Johnson County is lower than in Illinois overall, where 5.9% of the population is Asian. Johnson County ranks 101st statewide in terms of Asian residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's Asian population has grown by an estimated 83.3%. Asian residents' share of Johnson County's population has remained roughly unchanged at 0.2%.

Johnson County is more Asian than neighboring Pope County (0% Asian). Johnson County is less Asian than neighboring Williamson County (1.4% Asian), Massac County (0.3% Asian), and Union County (0.6% Asian).

Johnson County's Hispanic Population

597 residents of Johnson County, or 4.5% of the population, identify as Hispanic. The share of Hispanic residents in Johnson County is considerably lower than in Illinois overall, where 18.8% of the population is Hispanic. Johnson County ranks 37th statewide in terms of Hispanic residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's Hispanic population has grown by an estimated 8.2%. Hispanic residents' share of Johnson County's population has remained roughly unchanged at 4.5%.

Johnson County is more Hispanic than neighboring Williamson County (2.9% Hispanic), Massac County (2.9% Hispanic), Pope County (3% Hispanic), and Pulaski County (1% Hispanic). Johnson County is less Hispanic than neighboring Union County (5.5% Hispanic).

Johnson County's Native American/Other Population

33 residents of Johnson County, or 0.2% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Johnson County is comparable to the share in Illinois overall, where 0.5% of the population is Native American/Other. Johnson County ranks 91st statewide in terms of Native American/Other residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's Native American/Other population has declined by an estimated 8.3%. Native American/Other residents' share of Johnson County's population has remained roughly unchanged at 0.2%.

Johnson County is more Native American/Other than neighboring Pulaski County (0.1% Native American/Other), and Union County (0.1% Native American/Other). Johnson County is less Native American/Other than neighboring Williamson County (0.3% Native American/Other), Massac County (0.3% Native American/Other), and Pope County (0.7% Native American/Other).

Johnson County's Multiracial Population

958 residents of Johnson County, or 7.2% of the population, identify as Multiracial. The share of Multiracial residents in Johnson County is slightly higher than in Illinois overall, where 3.4% of the population is Multiracial. Johnson County ranks 74th statewide in terms of Multiracial residents as a share of the population, out of 102 counties.

Since the 2020 Census, Johnson County's Multiracial population has grown by an estimated 146.9%. Multiracial residents' share of Johnson County's population has increased from 2.9% to 7.2%.

Johnson County is more Multiracial than neighboring Williamson County (3.2% Multiracial), Massac County (3.9% Multiracial), Pope County (2.8% Multiracial), Pulaski County (3.3% Multiracial), and Union County (3.4% Multiracial).

Sources: Most recent population estimates are from the 2020-2024 American Community Survey 5-Year Estimates. 2020 population counts and map data are from 2020 Census State Redistricting Data. Geographic data are from Census TIGER/Line Shapefiles.