COUNTY · OH
Warren County, Ohio
Warren County is a county in Ohio with FIPS code 39165 and an estimated population of 252,148 (Census 2023), 10th largest of 88 in the state.
County facts
- Name
- Warren County
- State
- Ohio
- Type
- county
- FIPS code
- 39165
- State FIPS
- 39
- Population (2023)
- 252,148
- Change since 2020
- +3.7%
- State rank
- 10 of 88
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Warren County?
Warren County, Ohio has the five-digit FIPS code 39165: 39 for the state and 165 for the county.
What state is Warren County in?
Warren County is in Ohio.
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.