• county
  • FIPS 29189
  • Largest town: Florissant

St. Louis County, Missouri

St. Louis County had 992,929 residents in the Census Vintage 2024 estimate, on 508.0 square miles of land. It is the most populous of Missouri's 115 county-equivalents.

Population
992,929
#1 of 115 in Missouri · #52 in US
Area
508.0 sq mi
#77 of 115 in Missouri · #2,045 in US
Density
1,955 / sq mi
#2 of 115 in Missouri · #75 in US
Median household income
$81,631
#5 of 115 in Missouri · #417 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

St. Louis County within Missouri. Pin: Jefferson City.

Measure from here

Tools and pages that start from St. Louis County

St. Louis County population, land area and income

St. Louis County had 992,929 residents in the Census Vintage 2024 estimate, on 508.0 square miles of land. It is the most populous of Missouri's 115 county-equivalents. That works out to 1,954.6 people per square mile, 20.3 times the US average of 96.3, and in the top tenth nationally.

The median county-equivalent in Missouri has 19,100 residents, so St. Louis County is 52.0 times that size.

Its SAIPE 2023 median household income of $81,631 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

992,929

3144th1st

52nd of 3,144 (US)

Land area

508 sq mi

3144th1st

2045th of 3,144 (US)

Density

1,954.6 / sq mi

3144th1st

75th of 3,144 (US)

Median household income

$81,631

3143rd1st

417th of 3,143 (US)

Rank within Missouri (115)

Population

992,929

115th1st

1st of 115 (MO)

Land area

508 sq mi

115th1st

77th of 115 (MO)

Density

1,954.6 / sq mi

115th1st

2nd of 115 (MO)

Median household income

$81,631

115th1st

5th of 115 (MO)

How St. Louis County's population changed since 2020

St. Louis County lost 10,447 residents between the July 2020 and July 2024 estimates, a drop of 1.0%. That ranks 96th of 115 in Missouri for growth. The median Missouri county changed by +1.4%, and the state as a whole by +1.5%.

Since the April 2020 estimates base, St. Louis County recorded 43,086 births and 47,550 deaths, a natural change of -4,464. Net international migration added +16,227 and net domestic migration, people moving to or from other US counties, came to -24,029. The largest single component was domestic migration, which removed 24,029 people.

1.00M2020998.8k2021991.9k2022990.9k2023992.9k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
43,086
Deaths
47,550
Net international migration
+16,227
Net domestic migration
-24,029
Change, July 2023 to July 2024
+2,054

Where St. Louis County is

The Census internal point of St. Louis County is at 38.640700, -90.446100. It sits in UTM zone 15N. The map shades Missouri's 115 county-equivalents by population change from 2020 to 2024, darker for faster growth, with St. Louis County outlined. Dots are towns of 1,000+ people with residents in it.

Pettis County: +1.8%Henry County: +2.7%Texas County: +5.7%Madison County: +1.8%St. Louis city: -6.9%Cole County: +1.3%Washington County: +0.6%Macon County: -0.1%Barton County: +0.8%Grundy County: +0.1%Cedar County: +5.7%Randolph County: -1.6%Ray County: +0.3%Caldwell County: +2.0%Benton County: +6.1%Douglas County: +5.9%Shannon County: +3.4%Dade County: +0.5%Wright County: +7.1%Gentry County: +2.6%Lawrence County: +3.0%Cooper County: +2.9%Hickory County: +5.6%Moniteau County: +0.5%Dent County: +2.3%Monroe County: +2.3%Maries County: +0.7%Bollinger County: +0.5%Clinton County: +2.4%Knox County: +0.0%Webster County: +7.8%Harrison County: +0.4%Pulaski County: -0.1%Adair County: +1.5%Warren County: +7.7%Daviess County: +1.3%Audrain County: -1.9%Howard County: -0.1%Linn County: +0.4%Saline County: -0.1%Miller County: +3.6%Dallas County: +4.3%Morgan County: +6.7%New Madrid County: -6.8%Newton County: +4.8%Oregon County: +1.0%Franklin County: +2.3%Greene County: +2.9%Ralls County: +1.4%Lafayette County: +1.4%Livingston County: +4.8%McDonald County: +3.3%Barry County: +3.1%Cape Girardeau County: +2.2%Carroll County: -0.6%Christian County: +7.6%Vernon County: +0.6%Carter County: +3.0%Andrew County: -0.1%Jasper County: +2.9%Worth County: -4.9%Lincoln County: +10.1%Marion County: -0.2%Holt County: +1.2%Howell County: +2.4%St. Francois County: +1.6%Chariton County: +0.1%Butler County: -0.6%Iron County: -1.0%Perry County: +0.7%Cass County: +5.3%St. Louis County: -1.0%Dunklin County: -4.3%Wayne County: -1.1%Ozark County: +6.7%Laclede County: +1.9%Reynolds County: -2.5%Lewis County: -1.9%Taney County: +1.2%Ripley County: +0.4%Ste. Genevieve County: +0.4%Scotland County: -0.1%Putnam County: -3.1%Schuyler County: +1.5%Shelby County: -2.8%Boone County: +4.4%Mercer County: -1.7%Platte County: +5.6%Camden County: +3.1%Bates County: +2.1%Johnson County: +3.4%Sullivan County: -3.8%Atchison County: -3.1%Scott County: -0.2%Montgomery County: +2.0%Jefferson County: +2.2%Clark County: -0.5%Callaway County: +1.8%St. Clair County: +5.4%Buchanan County: -1.1%Pemiscot County: -7.6%Polk County: +4.6%Phelps County: +2.5%Stone County: +4.6%Osage County: +1.7%Clay County: +3.6%Nodaway County: -2.4%Crawford County: -1.0%Jackson County: +1.4%St. Charles County: +4.3%Mississippi County: -3.1%Pike County: +3.1%Stoddard County: -0.7%Gasconade County: -0.7%DeKalb County: -14.8%
Change 2020 to 2024
  1. < -0.7%
  2. < +0.5%
  3. < +2.0%
  4. < +3.6%
  5. ≥ +3.6%
no data

Orange pin: St. Louis County internal point. Dark pin: Jefferson City.

Internal point

Decimal
38.640700, -90.446100
DMS
38°38'26.52"N 90°26'45.96"W
UTM
15N 722277.1E 4280000.4N
Geohash
9yzevf74m
Plus code
86CFJHR3+7H

Towns in St. Louis County

65 incorporated places of 1,000+ people have residents in St. Louis County, 663,681 people together, or 67% of the county. Each figure counts only the part of the town inside St. Louis County; towns marked "part" extend into another county. The largest is Florissant with 51,290.

  1. 01Florissant51,290
  2. 02Chesterfield49,465
  3. 03Wildwood35,082
  4. 04University City34,349
  5. 05Ballwin31,036
  6. 06Kirkwood29,348
  7. 07Maryland Heights27,671
  8. 08Hazelwood24,951
  9. 09Webster Groves23,525
  10. 10Creve Coeur18,533
  11. 11Manchester18,122
  12. 12Ferguson18,043
  13. 13Clayton17,512
  14. 14Overland15,547
  15. 15Eureka (part)13,198
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering St. Louis County

The Census 2024 county adjacency file lists 7 neighbors for St. Louis County, including 3 across a state line. The most populous is St. Charles County, MO, with 423,726 residents. Distances run between Census internal points in a straight line.

Distance to Jefferson City and the nearest big city

Jefferson City is 93.3 miles W of St. Louis County's internal point in a straight line. The nearest place of 100,000 or more is St. Louis, MO (population 279,695), 10.9 miles away. The nearest place of 10,000 or more is Creve Coeur, MO (population 18,533), 1.5 miles away.

St. Louis County FIPS code

The FIPS code of St. Louis County is 29189: state code 29 for Missouri plus county code 189. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $81,631.

Questions people ask

What is the population of St. Louis County, Missouri?

The Census Vintage 2024 estimate for July 1, 2024 is 992,929. That is down 10,447 people (1.0%) from the July 2020 estimate of 1,003,376.

What is the FIPS code of St. Louis County?

29189. The first two digits (29) are Missouri; the last three (189) identify the county.

What is the largest town in St. Louis County?

Florissant, with 51,290 residents inside St. Louis County in 2024.

Which counties border St. Louis County?

7 county-equivalents border it in the Census 2024 adjacency file: St. Charles County, MO; St. Louis city, MO; Madison County, IL; St. Clair County, IL; Jefferson County, MO; Franklin County, MO; Monroe County, IL.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.