O'Fallon, MO Demographics

A map of O'Fallon's Population by Race

O'Fallon, Missouri has an estimated population of 93,801, a slight increase from the 91,316 recorded in the 2020 Census. The population is 79.5% White, 5.5% Hispanic, 5.2% Black, 4.8% Asian, 4.3% Multiracial, and 0.6% Native American/Other. This demographic dot map shows the population of O'Fallon, with one dot drawn for each person counted by the Census, color-coded by race.

O'Fallon has become more racially diverse since the 2020 Census. It is 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 O'Fallon, that probability was 32.9% in 2020 and 35.8% in the most recent ACS estimates.

O'Fallon is ranked the 7th most populous place in Missouri, out of 1,082 places. This ranking is based on the Census definition of a place, which includes incorporated places like cities, towns, and villages, as well as unincorporated census-designated places (CDPs). O'Fallon was ranked the 7th most populous place in the 2020 Census.

O'Fallon's White Population

74,564 residents of O'Fallon, or 79.5% of the population, identify as White. The share of White residents in O'Fallon is slightly higher than in Missouri overall, where 76.3% of the population is White. O'Fallon ranks 870th statewide in terms of White residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's White population has remained roughly the same. White residents' share of O'Fallon's population has decreased from 81.4% to 79.5%.

O'Fallon is less White than neighboring Dardenne Prairie (85.1% White), St. Paul (92.1% White), Cottleville (80.6% White), Lake St. Louis (84.7% White), and Josephville (84% White).

O'Fallon's Black Population

4,908 residents of O'Fallon, or 5.2% of the population, identify as Black. The share of Black residents in O'Fallon is lower than in Missouri overall, where 10.9% of the population is Black. O'Fallon ranks 159th statewide in terms of Black residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's Black population has grown by an estimated 7.4%. Black residents' share of O'Fallon's population has remained roughly unchanged at 5.2%.

O'Fallon is more Black than neighboring Dardenne Prairie (3.4% Black), and St. Paul (1.6% Black). O'Fallon is less Black than neighboring Cottleville (7.1% Black), Lake St. Louis (5.5% Black), and Josephville (13.1% Black).

O'Fallon's Asian Population

4,526 residents of O'Fallon, or 4.8% of the population, identify as Asian. The share of Asian residents in O'Fallon is slightly higher than in Missouri overall, where 2.1% of the population is Asian. O'Fallon ranks 37th statewide in terms of Asian residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's Asian population has grown by an estimated 22.7%. Asian residents' share of O'Fallon's population has increased from 4.0% to 4.8%.

O'Fallon is more Asian than neighboring St. Paul (0.2% Asian), Cottleville (1.3% Asian), Lake St. Louis (1.9% Asian), and Josephville (0.2% Asian). O'Fallon is less Asian than neighboring Dardenne Prairie (5.6% Asian).

O'Fallon's Hispanic Population

5,200 residents of O'Fallon, or 5.5% of the population, identify as Hispanic. The share of Hispanic residents in O'Fallon is comparable to the share in Missouri overall, where 5.2% of the population is Hispanic. O'Fallon ranks 250th statewide in terms of Hispanic residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's Hispanic population has grown by an estimated 42.9%. Hispanic residents' share of O'Fallon's population has increased from 4.0% to 5.5%.

O'Fallon is more Hispanic than neighboring Dardenne Prairie (3.3% Hispanic), St. Paul (1.2% Hispanic), Cottleville (3.5% Hispanic), Lake St. Louis (2.5% Hispanic), and Josephville (0% Hispanic).

O'Fallon's Native American/Other Population

563 residents of O'Fallon, or 0.6% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in O'Fallon is comparable to the share in Missouri overall, where 0.7% of the population is Native American/Other. O'Fallon ranks 574th statewide in terms of Native American/Other residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's Native American/Other population has grown by an estimated 13.7%. Native American/Other residents' share of O'Fallon's population has remained roughly unchanged at 0.6%.

O'Fallon is more Native American/Other than neighboring Dardenne Prairie (0% Native American/Other), St. Paul (0% Native American/Other), and Josephville (0% Native American/Other). O'Fallon is less Native American/Other than neighboring Cottleville (1.2% Native American/Other).

O'Fallon's Multiracial Population

4,040 residents of O'Fallon, or 4.3% of the population, identify as Multiracial. The share of Multiracial residents in O'Fallon is comparable to the share in Missouri overall, where 4.8% of the population is Multiracial. O'Fallon ranks 476th statewide in terms of Multiracial residents as a share of the population, out of 1,082 places.

Since the 2020 Census, O'Fallon's Multiracial population has declined by an estimated 11.9%. Multiracial residents' share of O'Fallon's population has decreased from 5.0% to 4.3%.

O'Fallon is more Multiracial than neighboring Dardenne Prairie (2.6% Multiracial), and Josephville (2.7% Multiracial). O'Fallon is less Multiracial than neighboring St. Paul (4.8% Multiracial), Cottleville (6.3% Multiracial), and Lake St. Louis (4.8% 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.