County outline
Where Franklin County is located
Area breakdown
Land accounts for 99.1% of Franklin County’s measured area and water for 0.9%. Its combined area converts to 1,494.8 square kilometers or approximately 369,367 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 571.776 | 1,480.893 | 365,936.6 |
| Water | 5.36 | 13.882 | 3,430.4 |
| Total | 577.136 | 1,494.775 | 369,367 |
How Franklin County compares
By original Census land area, Franklin County ranks #90 of 105 in Kansas and #1756 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.784 times the Kansas county-equivalent median of 729.7 square miles. It accounts for 0.7% of the combined county land area in the state.
See the complete Kansas ranking · What counts as a county equivalent?
Population and density of Franklin County
The Census Bureau estimates that 26,299 people lived in Franklin County on July 1, 2025. That ranks #1,613 of 3,222 county equivalents nationally and #23 of 105 in Kansas. Since the April 1, 2020 estimates base of 25,997, the population has grown by 302 (+1.2%), compared with +1.3% for Kansas as a whole.
With 571.8 square miles of land, that is 46 people per square mile (18 per km²), placing Franklin County #1,632 nationally for density and #16 in Kansas. The median county equivalent has 47 people per square mile; the Kansas median is 8.1. Put another way, there are about 14 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 26,014 | 26,023 | 25,984 | 26,201 | 26,245 | 26,299 |
| Change | — | +9 | −39 | +217 | +44 | +54 |
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 Franklin County
8 incorporated places lie at least partly in Franklin County. Together they are home to 17,094 people (65%); the other 9,205 (35%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Ottawa city, with 12,716 residents in the county. Among places with at least 1,000 residents in 2020, Wellsville city grew fastest since then (+2.8%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Ottawa cityCounty seat | 12,716 | +0.7% | 10.7 |
| Wellsville city | 2,002 | +2.8% | 1.723 |
| Pomona city | 882 | −0.2% | 0.944 |
| Richmond city | 440 | −2.4% | 0.341 |
| Williamsburg city | 383 | −1.5% | 0.968 |
| Princeton city | 255 | +3.2% | 0.338 |
| Lane city | 244 | +1.7% | 0.233 |
| Rantoul city | 172 | +1.8% | 0.147 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Franklin County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Franklin County is a central county of the Ottawa, KS Micropolitan Statistical Area. Franklin County is the area’s only county equivalent, so the micro area has the same 571.8 square miles of land. By combined land it ranks #375 of 542 micropolitan areas, and #469 by population. It belongs to the Kansas City-Overland Park-Kansas City, MO-KS Combined Statistical Area.
ZIP codes
13 ZIP Code Tabulation Areas have land in Franklin County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.
66006660336604266064660676607666078660796608066092660956652466528
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 Franklin County
Franklin County shares a land border with 5 county equivalents. It has more land than 1 of them. The largest neighbor is Osage County (705.5 mi²) and the smallest is Douglas County (455.8 mi²). Together with its neighbors, Franklin County forms a block of 3,515.5 mi² of land, of which it holds 16.3%.
| Bordering county equivalent | Land mi² | Size vs. Franklin | Compare |
|---|---|---|---|
| Osage County | 705.5 | 1.2× larger | Compare |
| Coffey County | 626.9 | 1.1× larger | Compare |
| Anderson County | 579.6 | about the same | Compare |
| Miami County | 575.9 | about the same | Compare |
| Douglas County | 455.8 | 1.3× smaller | Compare |
How big is Franklin County compared with U.S. states?
Franklin County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.8 times as much. Kansas’s county land could hold about 143 areas the size of Franklin County.
Another way to picture it: the same land area would fill a square about 23.9 miles (38.5 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 Franklin County?
Franklin County has more land than 1,466 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 Franklin County at #1,851 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 Franklin County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1755 | St. Lucie County, Florida | 571.9 | Compare |
| #1756 | Franklin County, Kansas | 571.8 | This county |
| #1757 | Neosho County, Kansas | 571.5 | 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 38.558019, -95.278962. 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: 1,480,893,014 m²; AWATER: 13,882,665 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 Franklin County?
Franklin County, Kansas has 571.8 square miles (1,480.9 km²) of land and 5.36 square miles of water, for a total area of 577.1 square miles. It ranks #1756 of 3,222 U.S. county equivalents by land area.
Is Franklin County the largest county in Kansas?
No. Franklin County ranks #90 of 105 in Kansas by land area. The largest is Butler County, with 1,429.7 square miles of land.
What counties border Franklin County?
Franklin County shares a land border with Miami County, Douglas County, Anderson County, Osage County, and Coffey County.
What is the population of Franklin County?
The Census Bureau estimates Franklin County had 26,299 residents on July 1, 2025, ranking #1,613 of 3,222 county equivalents. That is 46 people per square mile of land.
What is the county seat of Franklin County?
The county seat of Franklin County is Ottawa.
What cities and towns are in Franklin County?
Franklin County has 8 incorporated places. The most populous five are Ottawa city, Wellsville city, Pomona city, Richmond city, and Williamsburg city; 9,205 residents live outside any incorporated place.
Is Franklin County part of a metropolitan area?
Yes. It is a central county of the Ottawa, KS Micropolitan Statistical Area.
How many ZIP codes are in Franklin County?
13 ZIP Code Tabulation Areas have land in Franklin 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 Franklin County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.8 times as much land.
How many acres of land are in Franklin County?
The land measurement converts to approximately 365,937 acres. Including water, total area is approximately 369,367 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.