County Maps US

Knox County, Illinois

A county in Illinois, ranked 30 of 102 by population.

CountyFIPS 17095

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

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Population
47,767
-2,045 (-4.1%) since 2020
Land area
716.4
square miles. A further 0.5% of the total area is water
Population density
66.7
people per square mile, computed rather than published
County seat
Galesburg
Seat of county government.
Established
1825
200 years ago
Largest city
Galesburg city
Population 28,581.

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 Knox 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 Knox 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 650 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 Knox 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
Population47,76730th of 1021,041st of 3,144
Land area716.4 sq mi21st of 1021,264th of 3,144
Population density66.7 per sq mi36th of 1021,221st of 3,144
Median household income$57,03089th of 1022,328th of 3,143

Full data for Knox County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population47,767Vintage 2025 Population Estimates
Population in 202049,812Vintage 2025 Population Estimates
2020 estimates base?49,976Vintage 2025 Population Estimates
Land area716.4 sq mi2025 Gazetteer Files
Water area3.4 sq mi2025 Gazetteer Files
Total area719.8 sq mi2025 Gazetteer Files
Population density?66.7 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$57,030American Community Survey 2020-2024 5-Year Estimates
Median home value$111,900American Community Survey 2020-2024 5-Year Estimates
Median age42.6American Community Survey 2020-2024 5-Year Estimates
Households20,972American Community Survey 2020-2024 5-Year Estimates
Housing units23,758American 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
-233
431 births, 664 deaths
Net migration
+33
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 Knox 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
Warren CountyIllinois24 mi16,222
Fulton CountyIllinois24 mi32,901
Henry CountyIllinois24 mi48,095
Peoria CountyIllinois18 mi178,553
Stark CountyIllinois12 mi5,319
Mercer CountyIllinois6.0 mi15,229

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

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.