Delaware County Map

Delaware has 3 counties. Together they cover 1,949 sq mi of land and 1,059,952 people.

Boundaries from the 2025 Census cartographic boundary file, generalised so that no point moves by more than half a pixel at this width. Select any area to open its page.

Counties: 3; 50th most of the 51 states and DC
Population: 1,059,952; 45th largest
Land area: 1,949; square miles
Density: 544; people per square mile, computed

Download this map

Free to use and redistribute. The boundaries are public-domain Census Bureau data; attribution to County Maps US is appreciated but not required.

Satellite view

Aerial imagery of Delaware with the state boundary drawn on top. County lines are not drawn here: at this scale they would bury the picture, and the map above already carries them.

Aerial view of Delaware 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 381 by 800 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.

The extremes of Delaware

Most populous

New Castle County

588,026

Least populous

Kent County

194,786

Largest by land area

Sussex County

936.1 sq mi

Smallest by land area

New Castle County

426.3 sq mi

Most densely populated

New Castle County

1,379 per sq mi

Highest median household income

New Castle County

$91,166

Which is the largest county in Delaware? The answer depends on whether you mean area or population.

The counties, by shape

Every one, drawn to its own scale so the small ones stay recognisable. Shape alone is not a size comparison; the table below carries the areas.

What the map does not say

The counties of Delaware are nowhere near the same size. Sussex County covers 936.1 sq mi of land, 2.2 times the 426.3 sq mi of New Castle County. People are spread even less evenly: New Castle County packs 1,379 per sq mi while Sussex County holds 296 per sq mi.

They were not drawn in one sitting either. New Castle County dates to 1664, and the boundaries were still being redrawn when Sussex County was organised in 1683, 19 years later. Founding years come from Wikidata and are worth checking against the county's own history before citing.

Water is part of the picture too: 26.6% of Kent County is water, the most in the state, which is why its land area and total area disagree. And 2 of the 3 counties here share their names with counties in other states, so searching by name alone can land in the wrong place; the A to Z index lists every duplicate.

All 3 counties of Delaware

Sortable on any column. This table doubles as the text alternative to the map above: every area is a link, in alphabetical order, whether or not the map renders.

The 3 counties of Delaware, with population, land area, density, median household income, county seat and FIPS code.
Name	Population	Land area	Density	Median income	Seat	FIPS
Kent County	194,786	586.1 sq mi	332 per sq mi	$74,477	Dover	10001
New Castle County	588,026	426.3 sq mi	1,379 per sq mi	$91,166	Wilmington	10003
Sussex County	277,140	936.1 sq mi	296 per sq mi	$81,497	Georgetown	10005

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; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Looking for Delaware County?

Delaware is also the name of 6 counties in other states. If you meant one of those rather than the state of Delaware, they are listed here.

The ten most populous

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