Montgomery County, Pennsylvania

County seat: Norristown · Population 877,643 (2025) · 483 sq mi

Montgomery County is the 3rd most populous of Pennsylvania's 67 counties, with 877,643 people (2025 estimate). Its county seat is Norristown. It is part of the District 6 region, one of the 11 PennDOT engineering districts. The map shows its 24 cities and towns and the 6 neighboring counties.

Map of Montgomery County, Pennsylvania with cities, towns and the county boundary
Montgomery County, Pennsylvania with its cities and towns, unincorporated communities (CDPs) and neighboring counties. Boundaries: U.S. Census Bureau, 2025. Free to use with attribution (CC BY 4.0).
Download PDF (Letter) 248 KBPNG image 170 KBPennsylvania county map

Montgomery County facts

County seat
Norristown
Population (2025 estimate)
877,643 +2.5% since 2020
Land area
483 sq mi 47th largest of 67
Water area
4 sq mi
Population density
1,817 per sq mi
Established
1784
Same name
One of 18 Montgomery Counties in the US
Named after
Richard Montgomery, Montgomeryshire
Largest city
Lower Merion 64,691
Median household income
$113,915
Cities and towns
24 plus 48 CDPs
ZIP codes
71
Time zone
Eastern
FIPS code
42091

Cities and towns in Montgomery County

Montgomery County has 24 incorporated cities, towns and villages. Populations count the people living inside Montgomery County; cities that cross a county line also list the other counties.

NameTypePopulation 2025Also in
Norristown (county seat)Borough35,911
PottstownBorough23,322
LansdaleBorough18,986
ConshohockenBorough9,266
HatboroBorough8,593
SoudertonBorough7,288
AmblerBorough6,840
BridgeportBorough5,758
CollegevilleBorough5,287
RoyersfordBorough4,888
JenkintownBorough4,785
NarberthBorough4,479
TrappeBorough4,061
PennsburgBorough4,036
HatfieldBorough3,424
North WalesBorough3,422
East GreenvilleBorough3,154
TelfordBorough2,769Bucks County
RockledgeBorough2,613
Red HillBorough2,508
West ConshohockenBorough1,498
Bryn AthynBorough1,304
SchwenksvilleBorough1,265
Green LaneBorough471

Unincorporated communities (CDPs)

Census-designated places are communities without their own city government; the county provides their services.

CommunityPopulationAlso in
King of Prussia25,857
Horsham16,005
Willow Grove14,131
Montgomeryville13,388
Roslyn10,639
Bala Cynwyd10,227
Audubon9,229
Harleysville9,090
Sanatoga8,949
Kulpsville8,799
Ardmore8,625Delaware County
Glenside7,659
Plymouth Meeting7,502
Elkins Park7,213
Maple Glen6,643
Blue Bell6,424
Fort Washington6,271
Gilbertsville6,165
Penn Wynne6,070
Oreland5,953
Merion Station5,788
Wyndmoor5,633
Spring House5,137
Flourtown4,992
Eagleville4,985
Trooper4,907
Bryn Mawr4,346Delaware County
Oak Lane4,210
Skippack3,937
Stowe3,698
Halfway House3,688
Pottsgrove3,409
Wyncote3,389
Evansburg2,976
Wynnewood2,766
McKinley2,662
Mont Clare2,313
Spring Mount2,288
Melrose Park2,266
Cheltenham Village2,112
Villanova1,857Delaware County
Swedeland1,630
Woxall1,347
Rosemont1,289Delaware County
Oaks943
Swedesburg806
Arcadia University792
Haverford College141Delaware County

ZIP codes in Montgomery County

71 ZIP codes reach into Montgomery County. ZIP codes ignore county lines, so some also cover a neighboring county.

Population of Montgomery County, 2020–2025

Montgomery County grew by 21,251 people (+2.5%) between April 2020 and July 2025: 757 more births than deaths and a net gain of 20,571 people from migration.

Year (July 1)Population
2020856,829
2021864,286
2022865,483
2023870,108
2024875,160
2025877,643

Neighboring counties

Printable Montgomery County map

The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.

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Sources

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