County Maps US

Monmouth County, New Jersey

A county in New Jersey, ranked 6 of 21 by population.

CountyFIPS 34025

Within New Jersey
Monmouth County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Freehold, the county seat, located via the 2025 Census Gazetteer.

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Population
651,035
+8,650 (+1.3%) since 2020
Land area
468.2
square miles. A further 29.2% of the total area is water
Population density
1,390
people per square mile, computed rather than published
County seat
Freehold
Seat of county government.
Established
1683
342 years ago
Largest city
Long Branch city
Population 33,321.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Monmouth County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Monmouth County, New Jersey from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 800 by 667 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Monmouth County ranks

Position among the 21 counties of New Jersey, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn New JerseyNationally
Population651,0356th of 21110th of 3,144
Land area468.2 sq mi6th of 212,199th of 3,144
Population density1,390 per sq mi9th of 21118th of 3,144
Median household income$124,8455th of 2143rd of 3,143

Full data for Monmouth County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population651,035Vintage 2025 Population Estimates
Population in 2020642,385Vintage 2025 Population Estimates
2020 estimates base?643,488Vintage 2025 Population Estimates
Land area468.2 sq mi2025 Gazetteer Files
Water area193.2 sq mi2025 Gazetteer Files
Total area661.4 sq mi2025 Gazetteer Files
Population density?1,390 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$124,845American Community Survey 2020-2024 5-Year Estimates
Median home value$606,100American Community Survey 2020-2024 5-Year Estimates
Median age43.2American Community Survey 2020-2024 5-Year Estimates
Households251,712American Community Survey 2020-2024 5-Year Estimates
Housing units270,415American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
+715
6,457 births, 5,742 deaths
Net migration
+1,643
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Monmouth County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Ocean CountyNew Jersey45 mi673,746
Middlesex CountyNew Jersey23 mi883,335
Mercer CountyNew Jersey14 mi399,289
Richmond CountyNew York10 mi501,290
Queens CountyNew York8.6 mi2,358,182
Burlington CountyNew Jersey4.5 mi481,439

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

Side by side

All 21 counties of New Jersey

Open the interactive New Jersey county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.