The state of Pennsylvania has a total of 67 counties. Bucks County is the oldest (formed in 1682) and Lackawant to County is the newest (established in 1878).

Philadelphia County is the most populous, with a population of 1,526,006 people. Lycoming County has the most land area (3,222 km2), while Montour County has the smallest (342 km2).

Please find all Pennsylvania counties listed alphabetically below.

• Adams County, PA
• Allegheny County, PA
• Armstrong County, PA
• Beaver County, PA
• Bedford County, PA
• Berks County, PA
• Blair County, PA
• Bradford County, PA
• Bucks County, PA
• Butler County, PA
• Cambria County, PA
• Cameron County, PA
• Carbon County, PA
• Centre County, PA
• Chester County, PA
• Clarion County, PA
• Clearfield County, PA
• Clinton County, PA
• Columbia County, PA
• Crawford County, PA
• Cumberland County, PA
• Dauphin County, PA
• Delaware County, PA
• Elk County, PA
• Erie County, PA
• Fayette County, PA
• Forest County, PA
• Franklin County, PA
• Fulton County, PA
• Greene County, PA
• Huntingdon County, PA
• Indiana County, PA
• Jefferson County, PA
• Juniata County, PA
• Lackawanna County, PA
• Lancaster County, PA
• Lawrence County, PA
• Lebanon County, PA
• Lehigh County, PA
• Luzerne County, PA
• Lycoming County, PA
• McKean County, PA
• Mercer County, PA
• Mifflin County, PA
• Monroe County, PA
• Montgomery County, PA
• Montour County, PA
• Northampton County, PA
• Northumberland County, PA
• Perry County, PA
• Philadelphia County, PA
• Pike County, PA
• Potter County, PA
• Schuylkill County, PA
• Snyder County, PA
• Somerset County, PA
• Sullivan County, PA
• Susquehanna County, PA
• Tioga County, PA
• Union County, PA
• Venango County, PA
• Warren County, PA
• Washington County, PA
• Wayne County, PA
• Westmoreland County, PA
• Wyoming County, PA
• York County, PA