Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/PA/LARGEST-POPULATION

ZIP Codes With the Largest Population in Pennsylvania

What this measures. Population of the Census tabulation area, ACS 5-year estimate. Source: Census American Community Survey, data release 2026-10-12.

# ZIP City County Population
1 19124 Philadelphia Philadelphia 71,004
2 17603 Lancaster Lancaster 67,571
3 19120 Philadelphia Philadelphia 66,469
4 19111 Philadelphia Philadelphia 66,283
5 19143 Philadelphia Philadelphia 62,572
6 19446 Lansdale Montgomery 61,848
7 19149 Philadelphia Philadelphia 56,914
8 19020 Bensalem Bucks 56,809
9 17331 Hanover York 56,443
10 15601 Greensburg Westmoreland 56,425
11 17601 Lancaster Lancaster 56,382
12 19320 Coatesville Chester 55,941
13 19104 Philadelphia Philadelphia 55,172
14 19382 West Chester Chester 54,127
15 19067 Morrisville Bucks 53,885
16 19335 Downingtown Chester 53,629
17 19134 Philadelphia Philadelphia 53,594
18 19140 Philadelphia Philadelphia 53,385
19 17602 Lancaster Lancaster 52,217
20 18102 Allentown Lehigh 51,001
21 19144 Philadelphia Philadelphia 50,580
22 19148 Philadelphia Philadelphia 50,400
23 15301 Washington Washington 50,348
24 19380 West Chester Chester 49,856
25 19464 Pottstown Montgomery 49,101
26 18103 Allentown Lehigh 48,746
27 18104 Allentown Lehigh 48,683
28 15642 Irwin Westmoreland 46,325
29 17543 Lititz Lancaster 45,912
30 18042 Easton Northampton 45,532
31 19460 Phoenixville Chester 45,423
32 19403 Norristown Montgomery 44,017
33 15317 Canonsburg Washington 43,871
34 19131 Philadelphia Philadelphia 43,776
35 15237 Pittsburgh Allegheny 43,588
36 17050 Mechanicsburg Cumberland 43,571
37 19426 Collegeville Montgomery 43,460
38 19145 Philadelphia Philadelphia 43,440
39 19401 Norristown Montgomery 43,359
40 18974 Warminster Bucks 43,122
41 17701 Williamsport Lycoming 43,104
42 19139 Philadelphia Philadelphia 43,090
43 15108 Coraopolis Allegheny 42,799
44 17055 Mechanicsburg Cumberland 42,006
45 18702 Wilkes Barre Luzerne 41,970
46 19121 Philadelphia Philadelphia 41,574
47 19082 Upper Darby Delaware 41,541
48 19146 Philadelphia Philadelphia 41,058
49 16801 State College Centre 40,774
50 18017 Bethlehem Northampton 40,640

Showing the top 50 of 1,833 ZIP codes in Pennsylvania that have this figure . 19124 ranks 1st at 71,004, against 40,640 in 50th place.

Other rankings for Pennsylvania

Cite this page

zipcodes.pro. “ZIP Codes With the Largest Population in Pennsylvania.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/pa/largest-population

Underlying data is public domain or openly licensed — sources, vintages and licences.