Williamsport
- County:
- Lycoming County
- County Seat:
- Yes
- Area (mi²):
- 8.777
- State:
- Pennsylvania
Williamsport is a city located in Lycoming County, Pennsylvania. Williamsport has a 2026 population of 27,628. It is also the county seat of Lycoming County. Williamsport is currently declining at a rate of -0.16% annually and its population has decreased by -0.43% since the most recent census, which recorded a population of 27,746 in 2020.