COUNTY · PA
Philadelphia County, Pennsylvania
Philadelphia County is a county in Pennsylvania with FIPS code 42101 and an estimated population of 1,550,542 (Census 2023), 1st largest of 67 in the state.
County facts
- Name
- Philadelphia County
- State
- Pennsylvania
- Type
- county
- FIPS code
- 42101
- State FIPS
- 42
- Population (2023)
- 1,550,542
- Change since 2020
- -3.1%
- State rank
- 1 of 67
Population is the Census Bureau’s Vintage 2023 estimate.
Major cities in Philadelphia County
Other counties in Pennsylvania
Questions
What is the FIPS code for Philadelphia County?
Philadelphia County, Pennsylvania has the five-digit FIPS code 42101: 42 for the state and 101 for the county.
What state is Philadelphia County in?
Philadelphia County is in Pennsylvania.
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.