COUNTY · NY
Jefferson County, New York
Jefferson County is a county in New York with FIPS code 36045 and an estimated population of 114,787 (Census 2023), 25th largest of 62 in the state.
County facts
- Name
- Jefferson County
- State
- New York
- Type
- county
- FIPS code
- 36045
- State FIPS
- 36
- Population (2023)
- 114,787
- Change since 2020
- -1.1%
- State rank
- 25 of 62
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Jefferson County?
Jefferson County, New York has the five-digit FIPS code 36045: 36 for the state and 045 for the county.
What state is Jefferson County in?
Jefferson County is in New York.
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.