COUNTY · MO
Mercer County, Missouri
Mercer County is a county in Missouri with FIPS code 29129 and an estimated population of 3,469 (Census 2023), 114th largest of 115 in the state.
County facts
- Name
- Mercer County
- State
- Missouri
- Type
- county
- FIPS code
- 29129
- State FIPS
- 29
- Population (2023)
- 3,469
- Change since 2020
- -1.3%
- State rank
- 114 of 115
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Mercer County?
Mercer County, Missouri has the five-digit FIPS code 29129: 29 for the state and 129 for the county.
What state is Mercer County in?
Mercer 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.