Rock Island County Demographics

A map of Rock Island County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	96,160	97,689	67.4%	67.5%
Hispanic	20,305	19,842	14.2%	13.7%
Black	15,568	16,169	10.9%	11.2%
Multiracial	6,289	6,182	4.4%	4.3%
Asian	3,770	4,033	2.6%	2.8%
Native American/Other	665	757	0.5%	0.5%

Rock Island County, Illinois has an estimated population of 142,757, a slight decrease from the 144,672 recorded in the 2020 Census. The population is 67.4% White, 14.2% Hispanic, 10.9% Black, 4.4% Multiracial, 2.6% Asian, and 0.5% Native American/Other. This demographic dot map shows the population of Rock Island County, with one dot drawn for each person counted by the Census, color-coded by race.

Rock Island is about as racially diverse as it was in 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 Rock Island County, that probability was 51.0% in 2020 and 51.1% in the most recent ACS estimates.

Rock Island County is ranked the 14th most populous county in Illinois, out of 102 counties. Rock Island County was ranked the 14th most populous county in the 2020 Census.

Rock Island County's White Population

96,160 residents of Rock Island County, or 67.4% of the population, identify as White. The share of White residents in Rock Island County is higher than in Illinois overall, where 58.1% of the population is White. Rock Island County ranks 90th statewide in terms of White residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's White population has declined by an estimated 1.6%. White residents' share of Rock Island County's population has remained roughly unchanged at 67.4%.

Rock Island County is less White than neighboring Scott County (77% White), Mercer County (93.1% White), Clinton County (89% White), Henry County (87% White), and Muscatine County (75% White).

Rock Island County's Black Population

15,568 residents of Rock Island County, or 10.9% of the population, identify as Black. The share of Black residents in Rock Island County is slightly lower than in Illinois overall, where 13.3% of the population is Black. Rock Island County ranks 15th statewide in terms of Black residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's Black population has declined by an estimated 3.7%. Black residents' share of Rock Island County's population has remained roughly unchanged at 10.9%.

Rock Island County is more Black than neighboring Scott County (7.1% Black), Mercer County (0.6% Black), Clinton County (3.1% Black), Henry County (1% Black), and Muscatine County (2.2% Black).

Rock Island County's Asian Population

3,770 residents of Rock Island County, or 2.6% of the population, identify as Asian. The share of Asian residents in Rock Island County is slightly lower than in Illinois overall, where 5.9% of the population is Asian. Rock Island County ranks 12th statewide in terms of Asian residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's Asian population has declined by an estimated 6.5%. Asian residents' share of Rock Island County's population has remained roughly unchanged at 2.6%.

Rock Island County is more Asian than neighboring Mercer County (0.4% Asian), Clinton County (0.7% Asian), Henry County (0.5% Asian), and Muscatine County (0.6% Asian). Rock Island County is less Asian than neighboring Scott County (2.8% Asian).

Rock Island County's Hispanic Population

20,305 residents of Rock Island County, or 14.2% of the population, identify as Hispanic. The share of Hispanic residents in Rock Island County is slightly lower than in Illinois overall, where 18.8% of the population is Hispanic. Rock Island County ranks 11th statewide in terms of Hispanic residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's Hispanic population has grown by an estimated 2.3%. Hispanic residents' share of Rock Island County's population has increased from 13.7% to 14.2%.

Rock Island County is more Hispanic than neighboring Scott County (7.4% Hispanic), Mercer County (3.4% Hispanic), Clinton County (3.6% Hispanic), and Henry County (6.9% Hispanic). Rock Island County is less Hispanic than neighboring Muscatine County (18.8% Hispanic).

Rock Island County's Native American/Other Population

665 residents of Rock Island County, or 0.5% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in Rock Island County is comparable to the share in Illinois overall, where 0.5% of the population is Native American/Other. Rock Island County ranks 26th statewide in terms of Native American/Other residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's Native American/Other population has declined by an estimated 12.2%. Native American/Other residents' share of Rock Island County's population has remained roughly unchanged at 0.5%.

Rock Island County is more Native American/Other than neighboring Mercer County (0.1% Native American/Other), Clinton County (0.2% Native American/Other), and Muscatine County (0.3% Native American/Other). Rock Island County is less Native American/Other than neighboring Scott County (0.6% Native American/Other), and Henry County (0.6% Native American/Other).

Rock Island County's Multiracial Population

6,289 residents of Rock Island County, or 4.4% of the population, identify as Multiracial. The share of Multiracial residents in Rock Island County is comparable to the share in Illinois overall, where 3.4% of the population is Multiracial. Rock Island County ranks 17th statewide in terms of Multiracial residents as a share of the population, out of 102 counties.

Since the 2020 Census, Rock Island County's Multiracial population has grown by an estimated 1.7%. Multiracial residents' share of Rock Island County's population has remained roughly unchanged at 4.4%.

Rock Island County is more Multiracial than neighboring Mercer County (2.4% Multiracial), Clinton County (3.4% Multiracial), Henry County (4% Multiracial), and Muscatine County (3.1% Multiracial). Rock Island County is less Multiracial than neighboring Scott County (5.1% 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.