COUNTY · MO
St. Louis County, Missouri
St. Louis County is a county in Missouri with FIPS code 29189 and an estimated population of 987,059 (Census 2023), 1st largest of 115 in the state.
County facts
- Name
- St. Louis County
- State
- Missouri
- Type
- county
- FIPS code
- 29189
- State FIPS
- 29
- Population (2023)
- 987,059
- Change since 2020
- -1.6%
- State rank
- 1 of 115
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for St. Louis County?
St. Louis County, Missouri has the five-digit FIPS code 29189: 29 for the state and 189 for the county.
What state is St. Louis County in?
St. Louis County is in Missouri.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.