County outline
Where Lyon County is located
Area breakdown
Land accounts for 99.1% of Lyon County’s measured area and water for 0.9%. Its combined area converts to 2,215.5 square kilometers or approximately 547,467 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 847.477 | 2,194.955 | 542,385.3 |
| Water | 7.94 | 20.565 | 5,081.6 |
| Total | 855.417 | 2,215.52 | 547,466.9 |
How Lyon County compares
By original Census land area, Lyon County ranks #42 of 105 in Kansas and #986 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.161 times the Kansas county-equivalent median of 729.7 square miles. It accounts for 1% of the combined county land area in the state.
See the complete Kansas ranking · What counts as a county equivalent?
Population and density of Lyon County
The Census Bureau estimates that 32,266 people lived in Lyon County on July 1, 2025. That ranks #1,427 of 3,222 county equivalents nationally and #18 of 105 in Kansas. Since the April 1, 2020 estimates base of 32,180, the population has grown by 86 (+0.3%), compared with +1.3% for Kansas as a whole.
With 847.5 square miles of land, that is 38 people per square mile (15 per km²), placing Lyon County #1,791 nationally for density and #17 in Kansas. The median county equivalent has 47 people per square mile; the Kansas median is 8.1. Put another way, there are about 17 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 32,110 | 32,025 | 32,007 | 32,205 | 32,351 | 32,266 |
| Change | — | −85 | −18 | +198 | +146 | −85 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Lyon County
9 incorporated places lie at least partly in Lyon County. Together they are home to 26,554 people (82.3%); the other 5,712 (17.7%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Emporia city, with 24,137 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Emporia cityCounty seat | 24,137 | −0% | 12.4 |
| Americus city | 782 | +0.5% | 1.083 |
| Olpe city | 529 | +1.9% | 0.703 |
| Hartford city | 360 | +1.4% | 0.396 |
| Neosho Rapids city | 238 | +0.4% | 0.505 |
| Reading city | 183 | +1.1% | 0.213 |
| Allen city | 163 | +1.2% | 0.276 |
| Admire city | 134 | +2.3% | 0.323 |
| Bushong city | 28 | 0% | 0.152 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Lyon County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Lyon County is a central county of the Emporia, KS Micropolitan Statistical Area. Its 2 county equivalents have 34,838 residents on 1,620.5 square miles of land; Lyon County accounts for 52.3% of the land and 92.6% of the residents. By combined land it ranks #100 of 542 micropolitan areas, and #394 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Lyon County | 32,266 | 847.5 |
| Chase County | 2,572 | 773.1 |
ZIP codes
12 ZIP Code Tabulation Areas have land in Lyon County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.
664136652366801668306683366835668466685466860668646686566868
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Lyon County
Lyon County shares a land border with 6 county equivalents. It has more land than 5 of them. The largest neighbor is Greenwood County (1,143.3 mi²) and the smallest is Coffey County (626.9 mi²). Together with its neighbors, Lyon County forms a block of 5,585.9 mi² of land, of which it holds 15.2%.
| Bordering county equivalent | Land mi² | Size vs. Lyon | Compare |
|---|---|---|---|
| Greenwood County | 1,143.3 | 1.3× larger | Compare |
| Wabaunsee County | 794.3 | 1.1× smaller | Compare |
| Chase County | 773.1 | 1.1× smaller | Compare |
| Osage County | 705.5 | 1.2× smaller | Compare |
| Morris County | 695.3 | 1.2× smaller | Compare |
| Coffey County | 626.9 | 1.4× smaller | Compare |
How big is Lyon County compared with U.S. states?
Lyon County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. Kansas’s county land could hold about 96 areas the size of Lyon County.
Another way to picture it: the same land area would fill a square about 29.1 miles (46.9 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Lyon County?
Lyon County has more land than 2,236 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Lyon County at #1,081 nationally by total area, 95 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.9%, compared with a national county-equivalent median of 1.2% — 0.2 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Lyon County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #985 | Benton County, Arkansas | 847.7 | Compare |
| #986 | Lyon County, Kansas | 847.5 | This county |
| #987 | Dickinson County, Kansas | 847.1 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 38.455403, -96.161641. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 2,194,956,555 m²; AWATER: 20,563,498 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Lyon County?
Lyon County, Kansas has 847.5 square miles (2,195 km²) of land and 7.94 square miles of water, for a total area of 855.4 square miles. It ranks #986 of 3,222 U.S. county equivalents by land area.
Is Lyon County the largest county in Kansas?
No. Lyon County ranks #42 of 105 in Kansas by land area. The largest is Butler County, with 1,429.7 square miles of land.
What counties border Lyon County?
Lyon County shares a land border with Chase County, Greenwood County, Wabaunsee County, Osage County, Coffey County, and Morris County.
What is the population of Lyon County?
The Census Bureau estimates Lyon County had 32,266 residents on July 1, 2025, ranking #1,427 of 3,222 county equivalents. That is 38 people per square mile of land.
What is the county seat of Lyon County?
The county seat of Lyon County is Emporia.
What cities and towns are in Lyon County?
Lyon County has 9 incorporated places. The most populous five are Emporia city, Americus city, Olpe city, Hartford city, and Neosho Rapids city; 5,712 residents live outside any incorporated place.
Is Lyon County part of a metropolitan area?
Yes. It is a central county of the Emporia, KS Micropolitan Statistical Area, which has 2 county equivalents and 34,838 residents.
How many ZIP codes are in Lyon County?
12 ZIP Code Tabulation Areas have land in Lyon County, and 8 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Lyon County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.2 times as much land.
How many acres of land are in Lyon County?
The land measurement converts to approximately 542,385 acres. Including water, total area is approximately 547,467 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.