St. Charles County Demographics

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

Race	2024 Pop	2020 Pop	2024 %	2020 %
White	343,925	335,879	83.0%	82.9%
Black	20,824	20,672	5.0%	5.1%
Multiracial	17,946	19,433	4.3%	4.8%
Hispanic	17,405	16,011	4.2%	4.0%
Asian	12,472	11,068	3.0%	2.7%
Native American/Other	1,963	2,199	0.5%	0.5%

St. Charles County, Missouri has an estimated population of 414,535, a slight increase from the 405,262 recorded in the 2020 Census. The population is 83.0% White, 5.0% Black, 4.3% Multiracial, 4.2% Hispanic, 3.0% Asian, and 0.5% Native American/Other. This demographic dot map shows the population of St. Charles County, with one dot drawn for each person counted by the Census, color-coded by race.

St. Charles is about as racially diverse as it was in 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. Charles County, that probability was 30.6% in 2020 and 30.5% in the most recent ACS estimates.

St. Charles County is ranked the 3rd most populous county in Missouri, out of 115 counties. St. Charles County was ranked the 3rd most populous county in the 2020 Census.

St. Charles County's White Population

343,925 residents of St. Charles County, or 83.0% of the population, identify as White. The share of White residents in St. Charles County is higher than in Missouri overall, where 76.3% of the population is White. St. Charles County ranks 91st statewide in terms of White residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's White population has grown by an estimated 2.4%. White residents' share of St. Charles County's population has remained roughly unchanged at 83.0%.

St. Charles County is more White than neighboring St. Louis County (61.4% White), and St. Louis County (44.4% White). St. Charles County is less White than neighboring Calhoun County (94.3% White), Lincoln County (91.9% White), and Jersey County (94.6% White).

St. Charles County's Black Population

20,824 residents of St. Charles County, or 5.0% of the population, identify as Black. The share of Black residents in St. Charles County is lower than in Missouri overall, where 10.9% of the population is Black. St. Charles County ranks 22nd statewide in terms of Black residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's Black population has remained roughly the same. Black residents' share of St. Charles County's population has remained roughly unchanged at 5.0%.

St. Charles County is more Black than neighboring Calhoun County (1.5% Black), Lincoln County (1.7% Black), and Jersey County (0.6% Black). St. Charles County is less Black than neighboring St. Louis County (24% Black), and St. Louis County (42.1% Black).

St. Charles County's Asian Population

12,472 residents of St. Charles County, or 3.0% of the population, identify as Asian. The share of Asian residents in St. Charles County is comparable to the share in Missouri overall, where 2.1% of the population is Asian. St. Charles County ranks 6th statewide in terms of Asian residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's Asian population has grown by an estimated 12.7%. Asian residents' share of St. Charles County's population has remained roughly unchanged at 3.0%.

St. Charles County is more Asian than neighboring Calhoun County (0% Asian), Lincoln County (0.3% Asian), and Jersey County (0.7% Asian). St. Charles County is less Asian than neighboring St. Louis County (4.9% Asian), and St. Louis County (3.5% Asian).

St. Charles County's Hispanic Population

17,405 residents of St. Charles County, or 4.2% of the population, identify as Hispanic. The share of Hispanic residents in St. Charles County is comparable to the share in Missouri overall, where 5.2% of the population is Hispanic. St. Charles County ranks 23rd statewide in terms of Hispanic residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's Hispanic population has grown by an estimated 8.7%. Hispanic residents' share of St. Charles County's population has remained roughly unchanged at 4.2%.

St. Charles County is more Hispanic than neighboring St. Louis County (3.9% Hispanic), Calhoun County (0.8% Hispanic), Lincoln County (2.9% Hispanic), and Jersey County (1.6% Hispanic). St. Charles County is less Hispanic than neighboring St. Louis County (5.3% Hispanic).

St. Charles County's Native American/Other Population

1,963 residents of St. Charles 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 St. Charles County is comparable to the share in Missouri overall, where 0.7% of the population is Native American/Other. St. Charles County ranks 77th statewide in terms of Native American/Other residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's Native American/Other population has declined by an estimated 10.7%. Native American/Other residents' share of St. Charles County's population has remained roughly unchanged at 0.5%.

St. Charles County is more Native American/Other than neighboring Calhoun County (0.1% Native American/Other), Lincoln County (0.2% Native American/Other), and Jersey County (0.2% Native American/Other). St. Charles County is less Native American/Other than neighboring St. Louis County (0.6% Native American/Other), and St. Louis County (0.6% Native American/Other).

St. Charles County's Multiracial Population

17,946 residents of St. Charles County, or 4.3% of the population, identify as Multiracial. The share of Multiracial residents in St. Charles County is comparable to the share in Missouri overall, where 4.8% of the population is Multiracial. St. Charles County ranks 49th statewide in terms of Multiracial residents as a share of the population, out of 115 counties.

Since the 2020 Census, St. Charles County's Multiracial population has declined by an estimated 7.7%. Multiracial residents' share of St. Charles County's population has decreased from 4.8% to 4.3%.

St. Charles County is more Multiracial than neighboring Calhoun County (3.2% Multiracial), Lincoln County (3% Multiracial), Jersey County (2.4% Multiracial), and St. Louis County (4% Multiracial). St. Charles County is less Multiracial than neighboring St. Louis County (5.3% 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.