RANKING · 2025 ESTIMATES · 67 SHOWN OF 67

Largest by population, Pennsylvania counties

The most populous Pennsylvania counties as of the 2025 population estimates. This list covers the 67 counties in Pennsylvania that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDFastest growing Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS 2000

01Philadelphia County, PAPA1,574,281+4%

02Allegheny County, PAPA1,225,035−4%

03Montgomery County, PAPA877,643+17%

04Bucks County, PAPA647,828+8%

05Delaware County, PAPA580,937+5%

06Lancaster County, PAPA563,159+20%

07Chester County, PAPA557,116+29%

08York County, PAPA473,197+24%

09Berks County, PAPA440,072+18%

10Lehigh County, PAPA384,383+23%

11Westmoreland County, PAPA349,324−6%

12Luzerne County, PAPA332,126+4%

13Northampton County, PAPA324,411+21%

14Dauphin County, PAPA293,351+17%

15Cumberland County, PAPA277,270+30%

16Erie County, PAPA265,832−5%

17Lackawanna County, PAPA216,502+2%

18Washington County, PAPA210,802+4%

19Butler County, PAPA200,169+15%

20Monroe County, PAPA167,179+21%

21Beaver County, PAPA166,032−8%

22Franklin County, PAPA160,652+24%

23Centre County, PAPA157,393+16%

24Lebanon County, PAPA146,380+22%

25Schuylkill County, PAPA145,085−3%

26Cambria County, PAPA128,968−15%

27Fayette County, PAPA123,021−17%

28Blair County, PAPA119,541−7%

29Lycoming County, PAPA112,587−6%

30Mercer County, PAPA107,860−10%

31Adams County, PAPA107,594+18%

32Northumberland County, PAPA89,920−5%

33Lawrence County, PAPA83,911−11%

34Indiana County, PAPA82,878−8%

35Crawford County, PAPA81,792−9%

36Clearfield County, PAPA78,100−6%

37Somerset County, PAPA72,004−10%

38Columbia County, PAPA66,193+3%

39Carbon County, PAPA65,868+12%

40Armstrong County, PAPA63,698−12%

41Pike County, PAPA62,808+36%

42Bradford County, PAPA59,600−5%

43Wayne County, PAPA51,703+8%

44Venango County, PAPA49,346−14%

45Bedford County, PAPA47,480−5%

46Perry County, PAPA46,806+7%

47Mifflin County, PAPA46,127−1%

48Jefferson County, PAPA43,255−6%

49Huntingdon County, PAPA43,001−6%

50Union County, PAPA42,313+2%

51Tioga County, PAPA40,502−2%

52Snyder County, PAPA39,655+6%

53McKean County, PAPA38,984−15%

54Susquehanna County, PAPA38,237−9%

55Clinton County, PAPA37,870−0%

56Warren County, PAPA37,038−16%

57Clarion County, PAPA36,680−12%

58Greene County, PAPA33,885−17%

59Elk County, PAPA29,926−15%

60Wyoming County, PAPA25,790−8%

61Juniata County, PAPA23,403+3%

62Montour County, PAPA17,868−2%

63Potter County, PAPA15,897−12%

64Fulton County, PAPA14,483+2%

65Forest County, PAPA6,614+34%

66Sullivan County, PAPA5,856−11%

67Cameron County, PAPA4,211−30%

SHOWING 1–67 OF 67

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES