Ranking of Pennsylvania Counties By Population in 2018

Updated on June 18, 2025.

Based on the US Census Vintage data estimates, in 2018, the Population for Pennsylvania was 12.81M. Among all Pennsylvania counties, Philadelphia County had the highest population (1.59M), followed by Allegheny County (1.22M), and Montgomery County (827.00K).

The chart below shows the top 10 counties, and the table below shows the ranking of all Pennsylvania counties.

You can see similar ranking information for related topics, and for other states. You can also see the ranking of all counties in the United States.

See this for other years:
Ranking of Pennsylvania Counties By Population in 2018
Philadelphia
Allegheny
Montgomery
Bucks
Delaware
Lancaster
Chester
York
Berks
Lehigh
Ranking of Pennsylvania Counties By Population in 2018
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Rank County Population
1 Philadelphia County 1586422
2 Allegheny County 1217508
3 Montgomery County 826995
4 Bucks County 628183
5 Delaware County 565506
6 Lancaster County 543960
7 Chester County 522256
8 York County 448417
9 Berks County 420407
10 Lehigh County 368452
11 Westmoreland County 350600
12 Luzerne County 318093
13 Northampton County 304949
14 Dauphin County 276951
15 Erie County 271780
16 Cumberland County 251486
17 Lackawanna County 210301
18 Washington County 207114
19 Butler County 188031
20 Monroe County 169524
21 Beaver County 164669
22 Centre County 162895
23 Franklin County 154943
24 Schuylkill County 141758
25 Lebanon County 141116
26 Cambria County 131478
27 Fayette County 130452
28 Blair County 122567
29 Lycoming County 114175
30 Mercer County 110575
31 Adams County 103035
32 Northumberland County 91124
33 Lawrence County 86164
34 Crawford County 85111
35 Indiana County 84578
36 Clearfield County 79542
37 Somerset County 73951
38 Armstrong County 65411
39 Columbia County 65278
40 Carbon County 64169
41 Bradford County 60858
42 Pike County 55868
43 Wayne County 51364
44 Venango County 51283
45 Bedford County 48090
46 Mifflin County 46181
47 Perry County 46147
48 Huntingdon County 45385
49 Union County 45090
50 Jefferson County 43573
51 McKean County 41012
52 Tioga County 40725
53 Susquehanna County 40565
54 Snyder County 40474
55 Warren County 39528
56 Clarion County 38735
57 Clinton County 38647
58 Greene County 36639
59 Elk County 30096
60 Wyoming County 27070
61 Juniata County 24722
62 Montour County 18172
63 Potter County 16626
64 Fulton County 14486
65 Forest County 7294
66 Sullivan County 6057
67 Cameron County 4494