COUNTY · CT
Middlesex County, Connecticut
Middlesex County is a county in Connecticut with FIPS code 09007.
County facts
- Name
- Middlesex County
- State
- Connecticut
- Type
- county
- FIPS code
- 09007
- 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.
Other counties in Connecticut
Questions
What is the FIPS code for Middlesex County?
Middlesex County, Connecticut has the five-digit FIPS code 09007: 09 for the state and 007 for the county.
What state is Middlesex County in?
Middlesex 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.