St. Clair County Demographics

A map of St. Clair County's Population by Race

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	8,898	8,567	92.8%	92.3%
Multiracial	363	401	3.8%	4.3%
Hispanic	213	178	2.2%	1.9%
Black	77	26	0.8%	0.3%
Asian	20	19	0.2%	0.2%
Native American/Other	16	93	0.2%	1.0%

St. Clair County, Missouri has an estimated population of 9,587, an increase from the 9,284 recorded in the 2020 Census. The population is 92.8% White, 3.8% Multiracial, 2.2% Hispanic, 0.8% Black, 0.2% Asian, and 0.2% Native American/Other. This demographic dot map shows the population of St. Clair County, with one dot drawn for each person counted by the Census, color-coded by race.

St. Clair has become slightly less racially diverse since the 2020 Census. It is considerably less diverse than Missouri overall. Demographers use a diversity index to measure the probability that two randomly selected individuals belong to different racial or ethnic groups. In St. Clair County, that probability was 14.6% in 2020 and 13.7% in the most recent ACS estimates.

St. Clair County is ranked the 88th most populous county in Missouri, out of 115 counties. St. Clair County was ranked the 89th most populous county in the 2020 Census.

St. Clair County's White Population

8,898 residents of St. Clair County, or 92.8% of the population, identify as White. The share of White residents in St. Clair County is significantly higher than in Missouri overall, where 76.3% of the population is White. St. Clair County ranks 37th statewide in terms of White residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's White population has grown by an estimated 3.9%. White residents' share of St. Clair County's population has increased from 92.3% to 92.8%.

St. Clair County is more White than neighboring Cedar County (92.1% White), Henry County (91.3% White), Benton County (91.6% White), and Polk County (90.9% White). St. Clair County is less White than neighboring Hickory County (93.4% White).

St. Clair County's Black Population

77 residents of St. Clair County, or 0.8% of the population, identify as Black. The share of Black residents in St. Clair County is considerably lower than in Missouri overall, where 10.9% of the population is Black. St. Clair County ranks 98th statewide in terms of Black residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's Black population has grown by an estimated 196.2%. Black residents' share of St. Clair County's population has increased from 0.3% to 0.8%.

St. Clair County is more Black than neighboring Cedar County (0.5% Black), Hickory County (0.1% Black), and Polk County (0.7% Black). St. Clair County is less Black than neighboring Benton County (1% Black).

St. Clair County's Asian Population

20 residents of St. Clair County, or 0.2% of the population, identify as Asian. The share of Asian residents in St. Clair County is comparable to the share in Missouri overall, where 2.1% of the population is Asian. St. Clair County ranks 89th statewide in terms of Asian residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's Asian population has grown by an estimated 5.3%. Asian residents' share of St. Clair County's population has remained roughly unchanged at 0.2%.

St. Clair County is more Asian than neighboring Cedar County (0% Asian). St. Clair County is less Asian than neighboring Hickory County (0.5% Asian), and Polk County (0.8% Asian).

St. Clair County's Hispanic Population

213 residents of St. Clair County, or 2.2% of the population, identify as Hispanic. The share of Hispanic residents in St. Clair County is slightly lower than in Missouri overall, where 5.2% of the population is Hispanic. St. Clair County ranks 72nd statewide in terms of Hispanic residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's Hispanic population has grown by an estimated 19.7%. Hispanic residents' share of St. Clair County's population has remained roughly unchanged at 2.2%.

St. Clair County is more Hispanic than neighboring Hickory County (1.8% Hispanic), and Benton County (2% Hispanic). St. Clair County is less Hispanic than neighboring Henry County (3% Hispanic), and Polk County (3% Hispanic).

St. Clair County's Native American/Other Population

16 residents of St. Clair 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 St. Clair County is comparable to the share in Missouri overall, where 0.7% of the population is Native American/Other. St. Clair County ranks 20th statewide in terms of Native American/Other residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's Native American/Other population has declined by an estimated 82.8%. Native American/Other residents' share of St. Clair County's population has decreased from 1.0% to 0.2%.

St. Clair County is more Native American/Other than neighboring Hickory County (0.1% Native American/Other). St. Clair County is less Native American/Other than neighboring Cedar County (1.1% Native American/Other), Benton County (1.1% Native American/Other), and Polk County (1.2% Native American/Other).

St. Clair County's Multiracial Population

363 residents of St. Clair County, or 3.8% of the population, identify as Multiracial. The share of Multiracial residents in St. Clair County is comparable to the share in Missouri overall, where 4.8% of the population is Multiracial. St. Clair County ranks 70th statewide in terms of Multiracial residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Clair County's Multiracial population has declined by an estimated 9.5%. Multiracial residents' share of St. Clair County's population has decreased from 4.3% to 3.8%.

St. Clair County is more Multiracial than neighboring Polk County (3.3% Multiracial). St. Clair County is less Multiracial than neighboring Cedar County (4% Multiracial), Henry County (4.5% Multiracial), Hickory County (4.2% Multiracial), and Benton County (4.1% 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.