COUNTY · ME
Penobscot County, Maine
Penobscot County is a county in Maine with FIPS code 23019 and an estimated population of 155,312 (Census 2023), 3rd largest of 16 in the state.
County facts
- Name
- Penobscot County
- State
- Maine
- Type
- county
- FIPS code
- 23019
- State FIPS
- 23
- Population (2023)
- 155,312
- Change since 2020
- +2.1%
- State rank
- 3 of 16
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Penobscot County?
Penobscot County, Maine has the five-digit FIPS code 23019: 23 for the state and 019 for the county.
What state is Penobscot County in?
Penobscot County is in Maine.
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.