County Maps US

Thomas County, Kansas

A county in Kansas, ranked 49 of 105 by population.

CountyFIPS 20193

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

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Population
7,725
-201 (-2.5%) since 2020
Land area
1,075
square miles. A further 0.0% of the total area is water
Population density
7.2
people per square mile, computed rather than published
County seat
Colby
Seat of county government.
Established
1885
140 years ago
Largest city
Colby city
Population 5,489.

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 Thomas 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 Thomas County, Kansas 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 685 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 Thomas County ranks

Position among the 105 counties of Kansas, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn KansasNationally
Population7,72549th of 1052,593rd of 3,144
Land area1,075 sq mi10th of 105596th of 3,144
Population density7.2 per sq mi59th of 1052,678th of 3,144
Median household income$71,32527th of 1051,099th of 3,143

Full data for Thomas County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population7,725Vintage 2025 Population Estimates
Population in 20207,926Vintage 2025 Population Estimates
2020 estimates base?7,924Vintage 2025 Population Estimates
Land area1,075 sq mi2025 Gazetteer Files
Water area0.11 sq mi2025 Gazetteer Files
Total area1,075 sq mi2025 Gazetteer Files
Population density?7.2 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$71,325American Community Survey 2020-2024 5-Year Estimates
Median home value$172,700American Community Survey 2020-2024 5-Year Estimates
Median age35.3American Community Survey 2020-2024 5-Year Estimates
Households3,139American Community Survey 2020-2024 5-Year Estimates
Housing units3,575American 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
+38
118 births, 80 deaths
Net migration
-64
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 6 areas bordering Thomas 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
Rawlins CountyKansas35 mi2,431
Logan CountyKansas31 mi2,661
Sheridan CountyKansas30 mi2,427
Sherman CountyKansas30 mi5,763
Gove CountyKansas4.9 mi2,631
Decatur CountyKansas1.1 mi2,716

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

All 105 counties of Kansas

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

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