RANKING · 2010 CENSUS · 67 SHOWN OF 67

Largest by population, Pennsylvania counties · 2010

The most populous us counties as of the 2023 estimates. This list covers the 67 counties in Pennsylvania that qualify, ranked against each other statewide.

PennsylvaniaAll states All rankings

SAME RANKING BYCities States Metros ZIP codes

RELATEDFastest growing Fastest shrinking Most densely populated Most sparsely populated Best broadband access Worst broadband access

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPTOTAL POPULATIONVS 2000

01Philadelphia County, PAPA1,574,2811,526,006+1%

02Allegheny County, PAPA1,225,0351,223,348−5%

03Montgomery County, PAPA877,643799,874+7%

04Bucks County, PAPA647,828625,249+5%

05Delaware County, PAPA580,937558,979+1%

06Lancaster County, PAPA563,159519,445+10%

07Chester County, PAPA557,116498,886+15%

08York County, PAPA473,197434,972+14%

09Berks County, PAPA440,072411,442+10%

10Westmoreland County, PAPA349,324365,169−1%

11Lehigh County, PAPA384,383349,497+12%

12Luzerne County, PAPA332,126320,918+1%

13Northampton County, PAPA324,411297,735+11%

14Erie County, PAPA265,832280,566−0%

15Dauphin County, PAPA293,351268,100+6%

16Cumberland County, PAPA277,270235,406+10%

17Lackawanna County, PAPA216,502214,437+1%

18Washington County, PAPA210,802207,820+2%

19Butler County, PAPA200,169183,862+6%

20Beaver County, PAPA166,032170,539−6%

21Monroe County, PAPA167,179169,842+22%

22Centre County, PAPA157,393153,990+13%

23Franklin County, PAPA160,652149,618+16%

24Schuylkill County, PAPA145,085148,289−1%

25Cambria County, PAPA128,968143,679−6%

26Fayette County, PAPA123,021136,606−8%

27Lebanon County, PAPA146,380133,568+11%

28Blair County, PAPA119,541127,089−2%

29Mercer County, PAPA107,860116,638−3%

30Lycoming County, PAPA112,587116,111−3%

31Adams County, PAPA107,594101,407+11%

32Northumberland County, PAPA89,92094,528−0%

33Lawrence County, PAPA83,91191,108−4%

34Indiana County, PAPA82,87888,880−1%

35Crawford County, PAPA81,79288,765−2%

36Clearfield County, PAPA78,10081,642−2%

37Somerset County, PAPA72,00477,742−3%

38Armstrong County, PAPA63,69868,941−5%

39Columbia County, PAPA66,19367,295+5%

40Carbon County, PAPA65,86865,249+11%

41Bradford County, PAPA59,60062,622−0%

42Pike County, PAPA62,80857,369+24%

43Venango County, PAPA49,34654,984−4%

44Wayne County, PAPA51,70352,822+11%

45Bedford County, PAPA47,48049,762−0%

46Mifflin County, PAPA46,12746,682+0%

47Perry County, PAPA46,80645,969+5%

48Huntingdon County, PAPA43,00145,913+1%

49Jefferson County, PAPA43,25545,200−2%

50Union County, PAPA42,31344,947+8%

51McKean County, PAPA38,98443,450−5%

52Susquehanna County, PAPA38,23743,356+3%

53Tioga County, PAPA40,50241,981+1%

54Warren County, PAPA37,03841,815−5%

55Clarion County, PAPA36,68039,988−4%

56Snyder County, PAPA39,65539,702+6%

57Clinton County, PAPA37,87039,238+3%

58Greene County, PAPA33,88538,686−5%

59Elk County, PAPA29,92631,946−9%

60Wyoming County, PAPA25,79028,276+1%

61Juniata County, PAPA23,40324,636+8%

62Montour County, PAPA17,86818,267+0%

63Potter County, PAPA15,89717,457−3%

64Fulton County, PAPA14,48314,845+4%

65Forest County, PAPA6,6147,716+56%

66Sullivan County, PAPA5,8566,428−2%

67Cameron County, PAPA4,2115,085−15%

SHOWING 1–67 OF 67

Download CSV (full list, 67 rows)

UPDATED 2026-06-02 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES