List of counties in Pennsylvania

List of Pennsylvania counties:

1. Adams County, formed in 1800 from parts of York County. County seat: Gettysburg.
2. Allegheny County, formed in 1788 from parts of Washington and Westmoreland Counties. County seat: Pittsburgh.
3. Armstrong County, formed in 1800 from parts of Allegheny, Lycoming, and Westmoreland Counties. County seat: Kittanning.
4. Beaver County, formed in 1800 from parts of Allegheny and Washington Counties. County seat: Beaver.
5. Bedford County, formed in 1771 from parts of Cumberland County. County seat: Bedford.
6. Berks County, formed in 1752 from parts of Chester, Lancaster and Philadelphia Counties. County seat: Reading.
7. Blair County, formed in 1846 from parts of Huntingdon and Bedford Counties. County seat: Hollidaysburg.
8. Bradford County, formed in 1810 from parts of Luzerne and Lycoming Counties; originally called Ontario County, renamed as Bradford County in 1812. County seat: Towanda.
9. Bucks County, one of the original counties at the formation of Pennsylvania in 1682. County seat: Doylestown.
10. Butler County, formed in 1800 from parts of Allegheny County. County seat: Butler.
11. Cambria County, formed in 1804 from parts of Somerset and Huntingdon Counties. County seat: Ebensburg.
12. Cameron County, formed in 1860 from parts of Clinton, Elk, McKean, and Potter Counties. County seat: Emporium.
13. Carbon County, formed in 1843 from parts of Monroe and Northampton Counties. County seat: Jim Thorpe.
14. Centre County, formed in 1800 from parts of Lycoming, Mifflin, Northumberland, and Huntingdon Counties. County seat: Bellefonte.
15. Chester County, one of the original counties at the formation of Pennsylvania in 1682. County seat: West Chester.
16. Clarion County, formed in 1839 from parts of Venango and Armstrong Counties. County seat: Clarion.
17. Clearfield County, formed in 1804 from parts of Lycoming and Huntingdon Counties; Clearfield functioned as a part of Centre County for judiciary purposes until 1822. County seat: Clearfield.
18. Clinton County, formed in 1839 from parts of Lycoming and Centre Counties. County seat: Lock Haven.
19. Columbia County, formed in 1813 from parts of Northumberland and Luzerne Counties. County seat: Bloomsburg.
20. Crawford County, formed in 1800 from parts of Allegheny County. County seat: Meadville.
21. Cumberland County. formed in 1750 from parts of Lancaster County. County seat: Carlisle.
22. Dauphin County, formed in 1785 from parts of Lancaster County. County seat: Harrisburg.
23. Delaware County, formed in 1789 from parts of Chester County. County seat: Media.
24. Elk County, formed 1843 from parts of Jefferson, McKean, and Clearfield Counties. County seat: Ridgway.
25. Erie County, formed in 1800 from parts of Allegheny County; attached to Crawford County until 1803. County seat: Erie.
26. Fayette County, formed in 1783 from parts of Westmoreland County. County seat: Uniontown.
27. Forest County, formed in 1848 from parts of Jefferson County; attached to Jefferson County until 1857. County seat: Tionesta.
28. Franklin County, formed in 1784 from parts of Cumberland County. County seat: Chambersburg.
29. Fulton County, formed in 1850 from parts of Bedford County. County seat: McConnellsburg
30. Greene County, formed in 1796 from parts of Washington County. County seat: Waynesburg
31. Huntingdon County, formed in 1787 from parts of Bedford County. County seat: Huntingdon.
32. Indiana County, formed in 1803 from parts of Lycoming and Westmoreland Counties; it was attached to Westmoreland County until 1806. County seat: Indiana.
33. Jefferson County, formed in 1804 from parts of Lycoming County. Attached to Westmoreland County until 1806 and to Indiana County until 1830. County seat: Brookville.
34. Juniata County, formed 1831 from parts of Mifflin County. County seat: Mifflintown.
35. Lackawanna County, formed in 1878 from parts of Luzerne County. County seat: Scranton.
36. Lancaster County, formed in 1729 from parts of Chester County. County seat: Lancaster.
37. Lawrence County, formed in 1849 from parts of Beaver and Mercer Counties. County seat: New Castle.
38. Lebanon County, fourmed in 1813 from parts of Dauphin and Lancaster Counties. County seat: Lebanon.
39. Lehigh County, formed in 1812 from parts of Northampton County. County seat: Allentown.
40. Luzerne County, formed in 1786 from parts of Northumberland County. County seat: Wilkes-Barre.
41. Lycoming County, founed in 1795 from parts of Northumberland County. County seat: Williamsport.
42. McKean County, formed in 1804 from parts of Lycoming County; Attached to Centre County until 1814 and to Lycoming County until 1826 for judicial and elective purposes. McKean was fully organized only in 1826. County seat: Smethport.
43. Mercer County, formed in 1800 from parts of Allegheny County. County seat: Mercer.
44. Mifflin County, formed in 1789 from parts of Cumberland and Northumberland Counties. County seat: Lewistown.
45. Monroe County, formed in 1836 from parts of Pike and Northampton Counties. County seat: Stroudsburg.
46. Montgomery County, formed in 1784 from parts of Philadelphia County. County seat: Norristown.
47. Montour County, formed in 1850 from parts of Columbia County. County seat: Danville.
48. Northampton County, formed in 1752 from parts of Bucks County. County seat: Easton.
49. Northumberland County, formed in 1772 from parts of Lancaster, Berks, Bedford, Cumberland, and Northampton Counties. County seat: Sunbury.
50. Perry County, formed in 1820 from parts of Cumberland County. County seat: New Bloomfield.
51. Philadelphia County, one of the original counties at the formation of Pennsylvania in 1682. The city and county of Philadelphia were combined in 1854 and city and county offices merged in 1952.
52. Pike County, formed in 1814 from parts of Wayne County. County seat: Milford.
53. Potter County, Formed in 1804 from Lycoming county. Attached to Lycoming County until 18265 and to McKean County until 1835 for judicial purposes, Potter was not fully organized until 1835. County seat: Coudersport.
54. Schuylkill County, formed in 1811 from parts of Berks and Northampton Counties. County seat: Pottsville.
55. Snyder County, formed in 1855 from parts of Union County. County seat: Middleburg.
56. Somerset County, formed in 1795 from parts of Bedford County. County seat: Somerset.
57. Sullivan County, formed in 1847 from parts of Lycoming County; attached to Lycoming until 1848. County seat: Laporte.
58. Susquehanna County, formed in 1810 from parts of Luzerne County ; attached to Luzerne County until 1812. County seat: Montrose.
59. Tioga County, formed in 1804 from parts of Lycoming County; attached to Lycoming until 1812. County seat: Wellsboro.
60. Union County, formed in 1813 from parts of Northumberland County. County seat: Lewisburg.
61. Venango County, formed in 1800 from parts of Allegheny and Lycoming Counties; attached to until 1805. County seat: Franklin.
62. Warren County, formed in 1800 from parts of Allegheny and Lycoming counties; attached to Crawford County until 1805 and then to Venango until Warren was formally organized in 1819. County seat: Warren.
63. Washington County, formed in 1781 from parts of Westmoreland County. County seat: Washington.
64. Wayne County, formed in 1798 from parts of Northampton County. County seat: Honesdale.
65. Westmoreland County, formed in 1773 from parts of Bedford County. County seat: Greensburg.
66. Wyoming County, formed in 1842 from parts of Luzerne County. County seat: Tunkhannock.
67. York County, formed in 1749 from parts of Lancaster County. County seat: York.

map (http://quickfacts.census.gov/qfd/maps/pennsylvania_map.html)de:Liste der Counties in Pennsylvania fr:Comtés du Commonwealth de Pennsylvanie ja:ペンシルバニア州の郡一覧