Warren County, New Jersey

County seat: Belvidere · Population 112,953 (2025) · 357 sq mi

Warren County is the 19th most populous of New Jersey's 21 counties, with 112,953 people (2025 estimate). Its county seat is Belvidere. The map shows its 5 cities and towns and the 6 neighboring counties.

Map of Warren County, New Jersey with cities, towns and the county boundary
Warren County, New Jersey 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) 115 KBPNG image 120 KBNew Jersey county map

Warren County facts

County seat
Belvidere
Population (2025 estimate)
112,953 +3% since 2020
Land area
357 sq mi 9th largest of 21
Water area
6 sq mi
Population density
317 per sq mi
Established
1824
Same name
One of 14 Warren Counties in the US
Named after
Joseph Warren American doctor (1741-1775)
Largest city
Phillipsburg 15,456
Median household income
$100,869
Cities and towns
5 plus 36 CDPs
ZIP codes
22
Time zone
Eastern
FIPS code
34041

Cities and towns in Warren County

Warren County has 5 incorporated cities, towns and villages. Populations count the people living inside Warren County; cities that cross a county line also list the other counties.

NameTypePopulation 2025Also in
PhillipsburgTown15,456
HackettstownTown10,185
WashingtonBorough7,326
Belvidere (county seat)Town2,551
AlphaBorough2,362

Unincorporated communities (CDPs)

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

CommunityPopulationAlso in
Beattystown4,917
Panther Valley4,553
Greenwich2,679
Brass Castle1,936
Upper Pohatcong1,876
Oxford1,122
Vienna999
Stewartsville710
Brookfield673
Anderson607
Great Meadows604
Mountain Lake574
Lopatcong Overlook453
Johnsonburg406
Delaware Park374
Blairstown344
New Village335
Port Colden332
Finesville301
Silver Lake284
Harmony263
Asbury241
Hainesburg239
Mount Hermon207
Buttzville198
Marksboro193
Hope185
Columbia174
Port Murray138
Upper Stewartsville128
Broadway115
Hutchinson114
Bridgeville104
Delaware101
Brainards98
Allamuchy91

ZIP codes in Warren County

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

Population of Warren County, 2020–2025

Warren County grew by 3,323 people (+3%) between April 2020 and July 2025: 708 more deaths than births and a net gain of 4,091 people from migration.

Year (July 1)Population
2020109,431
2021110,580
2022111,018
2023111,651
2024112,424
2025112,953

Neighboring counties

Printable Warren 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.

Paste this code to embed the map on your site:

Sources

Back to the New Jersey county map with all 21 counties. Found an error? Tell us.