St. Mary, MO Demographics

A map of St. Mary's Population by Race

St. Mary, Missouri has an estimated population of 285, a decrease from the 309 recorded in the 2020 Census. The population is 87.7% White, 8.8% Multiracial, 3.2% Black, 0.4% Hispanic, 0.0% Asian, and 0.0% Native American/Other. This demographic dot map shows the population of St. Mary, with one dot drawn for each person counted by the Census, color-coded by race.

St. Mary 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. Mary, that probability was 23.0% in 2020 and 22.2% in the most recent ACS estimates.

St. Mary is ranked the 650th 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). St. Mary was ranked the 608th most populous place in the 2020 Census.

St. Mary's White Population

250 residents of St. Mary, or 87.7% of the population, identify as White. The share of White residents in St. Mary is considerably higher than in Missouri overall, where 76.3% of the population is White. St. Mary ranks 688th statewide in terms of White residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's White population has declined by an estimated 7.4%. White residents' share of St. Mary's population has remained roughly unchanged at 87.7%.

St. Mary is more White than neighboring Chester (68.1% White). St. Mary is less White than neighboring Kaskaskia (92.1% White), Lithium (100% White), Brewer (94.7% White), and Ozora (99.3% White).

St. Mary's Black Population

9 residents of St. Mary, or 3.2% of the population, identify as Black. The share of Black residents in St. Mary is lower than in Missouri overall, where 10.9% of the population is Black. St. Mary ranks 303rd statewide in terms of Black residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's Black population has grown by an estimated 50.0%. Black residents' share of St. Mary's population has increased from 1.9% to 3.2%.

St. Mary is more Black than neighboring Kaskaskia (0% Black), Lithium (0% Black), Brewer (0% Black), and Ozora (0% Black). St. Mary is less Black than neighboring Chester (27.4% Black).

St. Mary's Asian Population

0 residents of St. Mary, or 0.0% of the population, identify as Asian. The share of Asian residents in St. Mary is slightly lower than in Missouri overall, where 2.1% of the population is Asian. St. Mary ranks 615th statewide in terms of Asian residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's Asian population has grown from 0 to an estimated 0. Asian residents' share of St. Mary's population has remained roughly unchanged at 0.0%.

St. Mary is less Asian than neighboring Kaskaskia (7.9% Asian), and Ozora (0.3% Asian).

St. Mary's Hispanic Population

1 residents of St. Mary, or 0.4% of the population, identify as Hispanic. The share of Hispanic residents in St. Mary is slightly lower than in Missouri overall, where 5.2% of the population is Hispanic. St. Mary ranks 403rd statewide in terms of Hispanic residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's Hispanic population has declined by an estimated 88.9%. Hispanic residents' share of St. Mary's population has decreased from 2.9% to 0.4%.

St. Mary is more Hispanic than neighboring Kaskaskia (0% Hispanic), Lithium (0% Hispanic), Brewer (0% Hispanic), and Ozora (0.3% Hispanic). St. Mary is less Hispanic than neighboring Chester (3.3% Hispanic).

St. Mary's Native American/Other Population

0 residents of St. Mary, or 0.0% of the population, identify as American Indian/Alaska Native/Native Hawaiian/Pacific Islander/Other. The share of Native American/Other residents in St. Mary is comparable to the share in Missouri overall, where 0.7% of the population is Native American/Other. St. Mary ranks 729th statewide in terms of Native American/Other residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's Native American/Other population has declined by an estimated 100.0%. Native American/Other residents' share of St. Mary's population has remained roughly unchanged at 0.0%.

St. Mary is less Native American/Other than neighboring Chester (0.5% Native American/Other).

St. Mary's Multiracial Population

25 residents of St. Mary, or 8.8% of the population, identify as Multiracial. The share of Multiracial residents in St. Mary is slightly higher than in Missouri overall, where 4.8% of the population is Multiracial. St. Mary ranks 157th statewide in terms of Multiracial residents as a share of the population, out of 1,082 places.

Since the 2020 Census, St. Mary's Multiracial population has grown by an estimated 8.7%. Multiracial residents' share of St. Mary's population has increased from 7.4% to 8.8%.

St. Mary is more Multiracial than neighboring Kaskaskia (0% Multiracial), Lithium (0% Multiracial), Brewer (5.3% Multiracial), Ozora (0% Multiracial), and Chester (0.7% 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.