Municipalities in Pennsylvania by county and class COUNTYMUNICIPALITYCLASS Allegheny Aleppo Township 1st Township Allegheny Aspinwall Borough Borough Allegheny Avalon Borough Borough Allegheny Baldwin Borough Borough46 more rows •
Clairton. Duquesne. McKeesport. Pittsburgh (neighborhoods)
The region is comprised of 10 counties: Berks, Bucks, Chester, Delaware, Lancaster, Lebanon, Lehigh, Montgomery, Northampton, and Philadelphia. The three original counties, created by William Penn in 1682, include Philadelphia, Bucks, and Chester.
Allegheny County Pittsburgh / County
The top five largest counties in Pennsylvania are Lycoming (1,228.59 square miles), Bradford (1,147.40 square miles), Clearfield (1,144.72 square miles), Tioga (1,133.79 square miles), and Centre (1,109.92 square miles).
Adjacent counties Butler County (north) Armstrong County (northeast) Westmoreland County (east and south) Washington County (southwest) Beaver County (northwest)