RANKING · 2025 ESTIMATES · 67 SHOWN OF 67

Most population gained, Pennsylvania counties

Pennsylvania counties that added the most residents from the 2020 census to 2025, 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+22,703−60%

02Montgomery County, PAPA877,643+21,090−71%

03Cumberland County, PAPA277,270+17,801−3%

04York County, PAPA473,197+16,759−60%

05Northampton County, PAPA324,411+11,460−43%

06Berks County, PAPA440,072+11,223−70%

07Lancaster County, PAPA563,159+10,175−79%

08Lehigh County, PAPA384,383+9,826−53%

09Dauphin County, PAPA293,351+6,950−50%

10Luzerne County, PAPA332,126+6,532−173%

11Butler County, PAPA200,169+6,406−71%

12Franklin County, PAPA160,652+4,720−43%

13Pike County, PAPA62,808+4,273−77%

14Delaware County, PAPA580,937+4,107+28%

15Adams County, PAPA107,594+3,742−71%

16Lebanon County, PAPA146,380+3,123−53%

17Schuylkill County, PAPA145,085+2,036−191%

18Columbia County, PAPA66,193+1,466+54%

19Washington County, PAPA210,802+1,453−186%

20Bucks County, PAPA647,828+1,290−98%

21Carbon County, PAPA65,868+1,119−43%

22Perry County, PAPA46,806+964−60%

23Lackawanna County, PAPA216,502+606−111%

24Wayne County, PAPA51,703+548−93%

25Clinton County, PAPA37,870+420−43%

26Sullivan County, PAPA5,856+16−96%

27Mifflin County, PAPA46,127-16−106%

28Fulton County, PAPA14,483-73−117%

29Snyder County, PAPA39,655-81−109%

30Bedford County, PAPA47,480-97−105%

31Juniata County, PAPA23,403-106−105%

32Susquehanna County, PAPA38,237-197−111%

33Montour County, PAPA17,868-268−153%

34Wyoming County, PAPA25,790-279−7075%

35Cameron County, PAPA4,211-336−651%

36Forest County, PAPA6,614-359−349%

37Bradford County, PAPA59,600-367−120%

38Indiana County, PAPA82,878-368−5%

39Union County, PAPA42,313-368−107%

40Potter County, PAPA15,897-499−137%

41Tioga County, PAPA40,502-543−320%

42Clarion County, PAPA36,680-561−950%

43Centre County, PAPA157,393-779−107%

44Elk County, PAPA29,926-1,064−555%

45Huntingdon County, PAPA43,001-1,091−177%

46Venango County, PAPA49,346-1,108−39%

47Monroe County, PAPA167,179-1,148−103%

48Jefferson County, PAPA43,255-1,237+719%

49McKean County, PAPA38,984-1,448+21%

50Warren County, PAPA37,038-1,549+30%

51Lycoming County, PAPA112,587-1,601−220%

52Northumberland County, PAPA89,920-1,727−22%

53Armstrong County, PAPA63,698-1,860+71%

54Greene County, PAPA33,885-2,069−284%

55Somerset County, PAPA72,004-2,125−218%

56Crawford County, PAPA81,792-2,146−151%

57Lawrence County, PAPA83,911-2,159+35%

58Beaver County, PAPA166,032-2,183−53%

59Clearfield County, PAPA78,100-2,462−147%

60Mercer County, PAPA107,860-2,792+293%

61Blair County, PAPA119,541-3,281+135%

62Cambria County, PAPA128,968-4,504−57%

63Erie County, PAPA265,832-5,044−196%

64Westmoreland County, PAPA349,324-5,339+1528%

65Fayette County, PAPA123,021-5,783−276%

66Allegheny County, PAPA1,225,035-25,543−53%

67Philadelphia County, PAPA1,574,281-29,516−57%

SHOWING 1–67 OF 67

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