DuPage County, Illinois

A county in Illinois, ranked 2 of 102 by population.

CountyFIPS 17043

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

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Population
934,298
+2,825 (+0.3%) since 2020
Land area
327.9
square miles. A further 2.5% of the total area is water
Population density
2,849
people per square mile, computed rather than published
County seat
Wheaton
Seat of county government.
Established
1839
186 years ago
Largest city
Naperville city
Population 100,678 for the whole place, which extends beyond this county.

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 DuPage 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 DuPage County, Illinois 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 687 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.

Where DuPage County ranks

Position among the 102 counties of Illinois, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IllinoisNationally
Population934,2982nd of 10261st of 3,144
Land area327.9 sq mi87th of 1022,745th of 3,144
Population density2,849 per sq mi2nd of 10245th of 3,144
Median household income$112,0961st of 10282nd of 3,143

Full data for DuPage County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population934,298Vintage 2025 Population Estimates
Population in 2020931,473Vintage 2025 Population Estimates
2020 estimates base?933,029Vintage 2025 Population Estimates
Land area327.9 sq mi2025 Gazetteer Files
Water area8.5 sq mi2025 Gazetteer Files
Total area336.4 sq mi2025 Gazetteer Files
Population density?2,849 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$112,096American Community Survey 2020-2024 5-Year Estimates
Median home value$391,400American Community Survey 2020-2024 5-Year Estimates
Median age40.2American Community Survey 2020-2024 5-Year Estimates
Households350,758American Community Survey 2020-2024 5-Year Estimates
Housing units367,152American 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
+2,873
9,597 births, 6,724 deaths
Net migration
-1,271
More people moved out than moved in.

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

The 4 areas bordering DuPage 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
Cook CountyIllinois44 mi5,194,625
Kane CountyIllinois18 mi525,757
Will CountyIllinois15 mi712,253
Kendall CountyIllinois184 ft145,470

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

Side by side

All 102 counties of Illinois

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

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