RANKING · 2010 CENSUS · 67 SHOWN OF 67

Most population lost, Pennsylvania counties · 2010

Pennsylvania counties that lost the most residents from the 2000 census to 2010, by raw count of people rather than percentage. This list covers the 67 counties in Pennsylvania that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS 2000

01Allegheny County, PAPA1,225,035-58,318+6%

02Fayette County, PAPA123,021-12,038−466%

03Beaver County, PAPA166,032-10,873+132%

04Cambria County, PAPA128,968-8,919−14%

05Westmoreland County, PAPA349,324-4,824+1371%

06Lycoming County, PAPA112,587-3,933−395%

07Mercer County, PAPA107,860-3,655+415%

08Lawrence County, PAPA83,911-3,535+121%

09Armstrong County, PAPA63,698-3,451+218%

10Elk County, PAPA29,926-3,166−1453%

11Venango County, PAPA49,346-2,581+42%

12McKean County, PAPA38,984-2,486+108%

13Somerset County, PAPA72,004-2,281−226%

14Blair County, PAPA119,541-2,055+47%

15Warren County, PAPA37,038-2,048+73%

16Schuylkill County, PAPA145,085-2,047−9%

17Greene County, PAPA33,885-1,986−277%

18Clarion County, PAPA36,680-1,777−2792%

19Clearfield County, PAPA78,100-1,740−133%

20Crawford County, PAPA81,792-1,601−138%

21Cameron County, PAPA4,211-889−1557%

22Jefferson County, PAPA43,255-732+385%

23Indiana County, PAPA82,878-725+86%

24Potter County, PAPA15,897-623−146%

25Erie County, PAPA265,832-277−105%

26Bedford County, PAPA47,480-222−111%

27Bradford County, PAPA59,600-139−108%

28Sullivan County, PAPA5,856-128−128%

29Northumberland County, PAPA89,920-28−99%

30Montour County, PAPA17,868+31−94%

31Mifflin County, PAPA46,127+196−32%

32Wyoming County, PAPA25,790+196+4800%

33Huntingdon County, PAPA43,001+327−77%

34Fulton County, PAPA14,483+584+38%

35Tioga County, PAPA40,502+608+146%

36Susquehanna County, PAPA38,237+1,118−40%

37Lackawanna County, PAPA216,502+1,142−120%

38Clinton County, PAPA37,870+1,324+81%

39Luzerne County, PAPA332,126+1,668−119%

40Juniata County, PAPA23,403+1,815−17%

41Snyder County, PAPA39,655+2,156+149%

42Perry County, PAPA46,806+2,367−3%

43Forest County, PAPA6,614+2,770+1824%

44Columbia County, PAPA66,193+3,144+231%

45Union County, PAPA42,313+3,323−39%

46Washington County, PAPA210,802+4,923−392%

47Wayne County, PAPA51,703+5,100−34%

48Carbon County, PAPA65,868+6,447+230%

49Delaware County, PAPA580,937+8,115+153%

50Philadelphia County, PAPA1,574,281+8,456−112%

51Butler County, PAPA200,169+9,779−56%

52Adams County, PAPA107,594+10,115−22%

53Pike County, PAPA62,808+11,067−40%

54Lebanon County, PAPA146,380+13,241+101%

55Dauphin County, PAPA293,351+16,302+17%

56Centre County, PAPA157,393+18,232+52%

57Franklin County, PAPA160,652+20,305+147%

58Cumberland County, PAPA277,270+21,732+18%

59Bucks County, PAPA647,828+27,614−51%

60Northampton County, PAPA324,411+30,669+54%

61Monroe County, PAPA167,179+31,155−28%

62Lehigh County, PAPA384,383+37,407+78%

63Berks County, PAPA440,072+37,804+2%

64Lancaster County, PAPA563,159+48,787+2%

65Montgomery County, PAPA877,643+49,777−31%

66York County, PAPA473,197+53,221+26%

67Chester County, PAPA557,116+65,385+14%

SHOWING 1–67 OF 67

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS