1st most populous of 115
With 992,929 residents in 2024, St. Louis County ranks 1st by population among Missouri's 115 counties and is home to 15.9% of the state's residents.

St. Louis County has the largest economy in Missouri ($114.8 billion GDP) and the 2nd highest share of college graduates (47.4% of adults).
St. Louis County is home to 992,929 people (2024 estimate) on 508 square miles of land. This page brings together official U.S. Census Bureau population estimates since 2000, the components of change—births, deaths and migration—American Community Survey indicators on income, housing, poverty and education, BEA economic accounts and BLS unemployment.
Pick an indicator to see its long-run evolution.
U.S. Census Bureau: intercensal estimates 2000–2009, Vintage 2020 (2010–2019) and Vintage 2024 (2020–2024), July 1.
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate | 992,929 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 998,954 | 2010 · U.S. Census Bureau |
| Population, 2000 | 1,016,178 | July 1, 2000 · Census intercensal |
| Change since 2000 | −2.3% | 2000–2024 · Census |
| International migration | +6,550 | 2024 · Census Vintage 2024 |
| Domestic migration | −3,906 | 2024 · Census Vintage 2024 |
| Birth rate | 9.5 per 1,000 | 2024 · calculated |
| Death rate | 10.1 per 1,000 | 2024 · calculated |
| Population rank in Missouri | 1st of 115 | 2024 · calculated |
| Per capita personal income | $104,775 | BEA, 2024 · official |
| Gross domestic product | $114.8 billion | BEA, current dollars, 2024 · official |
| Median household income | $82,936 | ACS 2020–2024 5-year · official |
| Poverty rate | 9.8% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 47.4% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 8.4% | ACS 2020–2024 5-year · official |
| Median home value | $276,800 | ACS 2020–2024 5-year · official |
| Median gross rent | $1,209/month | ACS 2020–2024 5-year · official |
| Median age | 40.3 years | ACS 2020–2024 5-year · official |
| Households | 413,849 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 69.2% | ACS 2020–2024 5-year · official |
Comparable indicators for St. Louis County, Missouri and the United States.
| Indicator | County | Missouri | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | −1.2% | +1.5% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 9.5 | 10.8 | 10.6 | 2024 |
| Death rate (per 1,000) | 10.1 | 10.6 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 2.7 | 5.7 | 8.2 | 2024 |
| Population density (/mi²) | 1954.6 | 90.8 | 96.3 | 2024 |
| Per capita personal income | $104,775 | $64,920 | $73,204 | BEA, 2024 |
| Median household income | $82,936 | $70,702 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 9.8% | 12.6% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 47.4% | 32.4% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 8.4% | 4.5% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $276,800 | $230,300 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $1,209/month | $1,033/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 40.3 years | 39.0 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 69.2% | 68.1% | 65.2% | ACS 2020–2024 5-year |
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With 992,929 residents in 2024, St. Louis County ranks 1st by population among Missouri's 115 counties and is home to 15.9% of the state's residents.
Its population went from 1,016,178 in 2000 to 992,929 in 2024, a change of −2.3%, compared with +11.4% for Missouri as a whole.
In the year to July 2024 the county recorded 9,409 births and 10,029 deaths, so deaths outnumbered births by 620.
Annual Census estimates since 2000 put the county's highest population at 1,016,243 in 2001. The 2024 figure is 23,314 lower.
St. Louis County has about 1954.6 residents per square mile of land, ranking 2nd of 115 counties; Missouri averages 90.8.
With a median household income of $82,936 (ACS 2020–2024 5-year), the county ranks 7th of 115 Missouri counties; the state median is $70,702.
Its economy produced $114.8 billion of GDP in 2024 (BEA), 1st largest among 115 Missouri counties.
Real GDP grew 1.1% in 2024, adjusted for inflation (BEA, chained 2017 dollars).