West Mifflin, Pennsylvania

West Mifflin, Pennsylvania
Interactive map of West Mifflin, Pennsylvania
West Mifflin
West Mifflin
Coordinates: 40°22′5″N 79°53′51″W / 40.36806°N 79.89750°W / 40.36806; -79.89750
Country United States
State Pennsylvania
CountyAllegheny
Incorporated1788 (Mifflin Township)
 December 11, 1942 (Borough)
Government
 • MayorChris Kelly
Area
 • Total
14.50 sq mi (37.56 km2)
 • Land14.20 sq mi (36.79 km2)
 • Water0.29 sq mi (0.76 km2)  1.8%
Population
 (2020)
 • Total
19,589
 • Density1,386.6/sq mi (535.38/km2)
Time zoneUTC-5 (EST)
 • Summer (DST)UTC-4 (EDT)
ZIP code
15122
Area code878
FIPS code42-83512
Websitewww.westmifflin.gov

West Mifflin is a borough in Allegheny County, Pennsylvania, United States, located southeast of Pittsburgh. The population was 19,589 at the 2020 census. It is named after Thomas Mifflin, the first governor of Pennsylvania and a U.S. Founding Father.

Although the borough is heavily residential, it is home to one of America's oldest traditional amusement parks, Kennywood Park. Other employers include advanced naval nuclear propulsion technology research and development facility, Bettis Atomic Power Laboratory; monorail manufacturer Bombardier; US Steel's Mon Valley Works–Irvin Plant; Community College of Allegheny County's South Campus; and the Allegheny County Airport.