RANKING · 2010 CENSUS · 67 SHOWN OF 67

Most population gained, Pennsylvania counties · 2010

Pennsylvania counties that added 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

01Chester County, PAPA557,116+65,385+14%

02York County, PAPA473,197+53,221+26%

03Montgomery County, PAPA877,643+49,777−31%

04Lancaster County, PAPA563,159+48,787+2%

05Berks County, PAPA440,072+37,804+2%

06Lehigh County, PAPA384,383+37,407+78%

07Monroe County, PAPA167,179+31,155−28%

08Northampton County, PAPA324,411+30,669+54%

09Bucks County, PAPA647,828+27,614−51%

10Cumberland County, PAPA277,270+21,732+18%

11Franklin County, PAPA160,652+20,305+147%

12Centre County, PAPA157,393+18,232+52%

13Dauphin County, PAPA293,351+16,302+17%

14Lebanon County, PAPA146,380+13,241+101%

15Pike County, PAPA62,808+11,067−40%

16Adams County, PAPA107,594+10,115−22%

17Butler County, PAPA200,169+9,779−56%

18Philadelphia County, PAPA1,574,281+8,456−112%

19Delaware County, PAPA580,937+8,115+153%

20Carbon County, PAPA65,868+6,447+230%

21Wayne County, PAPA51,703+5,100−34%

22Washington County, PAPA210,802+4,923−392%

23Union County, PAPA42,313+3,323−39%

24Columbia County, PAPA66,193+3,144+231%

25Forest County, PAPA6,614+2,770+1824%

26Perry County, PAPA46,806+2,367−3%

27Snyder County, PAPA39,655+2,156+149%

28Juniata County, PAPA23,403+1,815−17%

29Luzerne County, PAPA332,126+1,668−119%

30Clinton County, PAPA37,870+1,324+81%

31Lackawanna County, PAPA216,502+1,142−120%

32Susquehanna County, PAPA38,237+1,118−40%

33Tioga County, PAPA40,502+608+146%

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

35Huntingdon County, PAPA43,001+327−77%

36Mifflin County, PAPA46,127+196−32%

37Wyoming County, PAPA25,790+196+4800%

38Montour County, PAPA17,868+31−94%

39Northumberland County, PAPA89,920-28−99%

40Sullivan County, PAPA5,856-128−128%

41Bradford County, PAPA59,600-139−108%

42Bedford County, PAPA47,480-222−111%

43Erie County, PAPA265,832-277−105%

44Potter County, PAPA15,897-623−146%

45Indiana County, PAPA82,878-725+86%

46Jefferson County, PAPA43,255-732+385%

47Cameron County, PAPA4,211-889−1557%

48Crawford County, PAPA81,792-1,601−138%

49Clearfield County, PAPA78,100-1,740−133%

50Clarion County, PAPA36,680-1,777−2792%

51Greene County, PAPA33,885-1,986−277%

52Schuylkill County, PAPA145,085-2,047−9%

53Warren County, PAPA37,038-2,048+73%

54Blair County, PAPA119,541-2,055+47%

55Somerset County, PAPA72,004-2,281−226%

56McKean County, PAPA38,984-2,486+108%

57Venango County, PAPA49,346-2,581+42%

58Elk County, PAPA29,926-3,166−1453%

59Armstrong County, PAPA63,698-3,451+218%

60Lawrence County, PAPA83,911-3,535+121%

61Mercer County, PAPA107,860-3,655+415%

62Lycoming County, PAPA112,587-3,933−395%

63Westmoreland County, PAPA349,324-4,824+1371%

64Cambria County, PAPA128,968-8,919−14%

65Beaver County, PAPA166,032-10,873+132%

66Fayette County, PAPA123,021-12,038−466%

67Allegheny County, PAPA1,225,035-58,318+6%

SHOWING 1–67 OF 67

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