COUNTY · CT
Fairfield County, Connecticut
Fairfield County is a county in Connecticut with FIPS code 09001.
County facts
- Name
- Fairfield County
- State
- Connecticut
- Type
- county
- FIPS code
- 09001
- State FIPS
- 09
Population is the Census Bureau’s Vintage 2023 estimate. Connecticut’s 2023 estimates use planning regions instead of counties, so county population is not available.
Questions
What is the FIPS code for Fairfield County?
Fairfield County, Connecticut has the five-digit FIPS code 09001: 09 for the state and 001 for the county.
What state is Fairfield County in?
Fairfield County is in Connecticut.
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.