Marion County Demographics

A map of Marion County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	32,978	33,150	89.1%	87.9%
Multiracial	1,562	1,817	4.2%	4.8%
Black	1,071	1,509	2.9%	4.0%
Hispanic	812	712	2.2%	1.9%
Native American/Other	320	192	0.9%	0.5%
Asian	257	349	0.7%	0.9%

Marion County, Illinois has an estimated population of 37,000, a slight decrease from the 37,729 recorded in the 2020 Census. The population is 89.1% White, 4.2% Multiracial, 2.9% Black, 2.2% Hispanic, 0.9% Native American/Other, and 0.7% Asian. This demographic dot map shows the population of Marion County, with one dot drawn for each person counted by the Census, color-coded by race.

Marion has become less 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 Marion County, that probability was 22.4% in 2020 and 20.2% in the most recent ACS estimates.

Marion County is ranked the 36th most populous county in Illinois, out of 102 counties. Marion County was ranked the 36th most populous county in the 2020 Census.

Marion County's White Population

32,978 residents of Marion County, or 89.1% of the population, identify as White. The share of White residents in Marion County is significantly higher than in Illinois overall, where 58.1% of the population is White. Marion County ranks 53rd statewide in terms of White residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's White population has remained roughly the same. White residents' share of Marion County's population has increased from 87.9% to 89.1%.

Marion County is more White than neighboring Jefferson County (83.6% White), and Fayette County (88.3% White). Marion County is less White than neighboring Clay County (94.8% White), Clinton County (90.1% White), and Effingham County (94.2% White).

Marion County's Black Population

1,071 residents of Marion County, or 2.9% of the population, identify as Black. The share of Black residents in Marion County is considerably lower than in Illinois overall, where 13.3% of the population is Black. Marion County ranks 41st statewide in terms of Black residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's Black population has declined by an estimated 29.0%. Black residents' share of Marion County's population has decreased from 4.0% to 2.9%.

Marion County is more Black than neighboring Clay County (0.3% Black), and Effingham County (0.3% Black). Marion County is less Black than neighboring Jefferson County (5.8% Black), Fayette County (3.2% Black), and Clinton County (3.1% Black).

Marion County's Asian Population

257 residents of Marion County, or 0.7% of the population, identify as Asian. The share of Asian residents in Marion County is lower than in Illinois overall, where 5.9% of the population is Asian. Marion County ranks 27th statewide in terms of Asian residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's Asian population has declined by an estimated 26.4%. Asian residents' share of Marion County's population has remained roughly unchanged at 0.7%.

Marion County is more Asian than neighboring Fayette County (0.2% Asian), Clay County (0.2% Asian), and Clinton County (0.6% Asian). Marion County is less Asian than neighboring Jefferson County (1% Asian), and Effingham County (0.8% Asian).

Marion County's Hispanic Population

812 residents of Marion County, or 2.2% of the population, identify as Hispanic. The share of Hispanic residents in Marion County is significantly lower than in Illinois overall, where 18.8% of the population is Hispanic. Marion County ranks 71st statewide in terms of Hispanic residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's Hispanic population has grown by an estimated 14.0%. Hispanic residents' share of Marion County's population has remained roughly unchanged at 2.2%.

Marion County is more Hispanic than neighboring Clay County (2% Hispanic). Marion County is less Hispanic than neighboring Jefferson County (2.8% Hispanic), Fayette County (3% Hispanic), Clinton County (4.1% Hispanic), and Effingham County (2.8% Hispanic).

Marion County's Native American/Other Population

320 residents of Marion County, or 0.9% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Marion County is comparable to the share in Illinois overall, where 0.5% of the population is Native American/Other. Marion County ranks 30th statewide in terms of Native American/Other residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's Native American/Other population has grown by an estimated 66.7%. Native American/Other residents' share of Marion County's population has remained roughly unchanged at 0.9%.

Marion County is more Native American/Other than neighboring Jefferson County (0.7% Native American/Other), Fayette County (0.3% Native American/Other), Clay County (0.3% Native American/Other), Clinton County (0.2% Native American/Other), and Effingham County (0.2% Native American/Other).

Marion County's Multiracial Population

1,562 residents of Marion County, or 4.2% of the population, identify as Multiracial. The share of Multiracial residents in Marion County is comparable to the share in Illinois overall, where 3.4% of the population is Multiracial. Marion County ranks 7th statewide in terms of Multiracial residents as a share of the population, out of 102 counties.

Since the 2020 Census, Marion County's Multiracial population has declined by an estimated 14.0%. Multiracial residents' share of Marion County's population has decreased from 4.8% to 4.2%.

Marion County is more Multiracial than neighboring Clay County (2.3% Multiracial), Clinton County (2% Multiracial), and Effingham County (1.6% Multiracial). Marion County is less Multiracial than neighboring Jefferson County (6% Multiracial), and Fayette County (5% 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.