
Castle Shannon
- County:
- Allegheny County
- County Seat:
- No
- Area (mi²):
- 1.598
- State:
- Pennsylvania
Castle Shannon is a borough located in Allegheny County, Pennsylvania. Castle Shannon has a 2025 population of 7,975. Castle Shannon is currently declining at a rate of -0.78% annually and its population has decreased by -3.8% since the most recent census, which recorded a population of 8,290 in 2020.
The average household income in Castle Shannon is $81,574 with a poverty rate of 8.45%. The median age in Castle Shannon is 41.9 years: 40.3 years for males, and 42.2 years for females.