Allentown
- County:
- Lehigh County
- County Seat:
- Yes
- Area (mi²):
- 17.564
- State:
- Pennsylvania
Allentown is a city located in Lehigh County, Pennsylvania. Allentown has a 2026 population of 127,138. It is also the county seat of Lehigh County. Allentown is currently growing at a rate of 0.97% annually and its population has increased by 1.12% since the most recent census, which recorded a population of 125,731 in 2020.