County outline
Where St. Francois County is located
Area breakdown
Land accounts for 99.4% of St. Francois County’s measured area and water for 0.6%. Its combined area converts to 1,177.6 square kilometers or approximately 290,991 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 451.886 | 1,170.379 | 289,207 |
| Water | 2.787 | 7.218 | 1,783.7 |
| Total | 454.673 | 1,177.598 | 290,990.7 |
How St. Francois County compares
By original Census land area, St. Francois County ranks #96 of 115 in Missouri and #2265 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.763 times the Missouri county-equivalent median of 592 square miles. It accounts for 0.7% of the combined county land area in the state.
See the complete Missouri ranking · What counts as a county equivalent?
Population and density of St. Francois County
The Census Bureau estimates that 67,809 people lived in St. Francois County on July 1, 2025. That ranks #817 of 3,222 county equivalents nationally and #17 of 115 in Missouri. Since the April 1, 2020 estimates base of 66,922, the population has grown by 887 (+1.3%), compared with +1.9% for Missouri as a whole.
With 451.9 square miles of land, that is 150 people per square mile (58 per km²), placing St. Francois County #772 nationally for density and #15 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 4.3 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 66,433 | 67,014 | 66,916 | 67,027 | 67,449 | 67,809 |
| Change | — | +581 | −98 | +111 | +422 | +360 |
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 St. Francois County
8 incorporated places lie at least partly in St. Francois County. Together they are home to 43,248 people (63.8%); the other 24,561 (36.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Farmington city, with 19,226 residents in the county. By land, Park Hills city is the largest at 20.3 mi². Among places with at least 1,000 residents in 2020, Farmington city grew fastest since then (+5.6%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Farmington cityCounty seat | 19,226 | +5.6% | 9.494 |
| Park Hills city | 8,753 | +1.8% | 20.3 |
| Bonne Terre city | 6,636 | −3.9% | 4.07 |
| Desloge city | 4,819 | +0% | 2.918 |
| Bismarck city | 1,224 | −0.6% | 0.996 |
| Leadwood city | 1,158 | −1.4% | 1.157 |
| Leadington city | 785 | +2.5% | 0.912 |
| Iron Mountain Lake city | 647 | +0.9% | 1.962 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside St. Francois County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
St. Francois County is a central county of the Farmington, MO Micropolitan Statistical Area. St. Francois County is the area’s only county equivalent, so the micro area has the same 451.9 square miles of land. By combined land it ranks #455 of 542 micropolitan areas, and #119 by population. It belongs to the St. Louis-St. Charles-Farmington, MO-IL Combined Statistical Area.
ZIP codes
15 ZIP Code Tabulation Areas have land in St. Francois County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.
630206302863036630876360163624636266362863630636376364063645636486365063653
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 St. Francois County
St. Francois County shares a land border with 6 county equivalents. Each of them has more land than St. Francois County. The largest neighbor is Washington County (759.9 mi²) and the smallest is Perry County (474.4 mi²). Together with its neighbors, St. Francois County forms a block of 3,886 mi² of land, of which it holds 11.6%.
| Bordering county equivalent | Land mi² | Size vs. St. Francois | Compare |
|---|---|---|---|
| Washington County | 759.9 | 1.7× larger | Compare |
| Jefferson County | 656 | 1.5× larger | Compare |
| Iron County | 550.3 | 1.2× larger | Compare |
| Ste. Genevieve County | 499.2 | 1.1× larger | Compare |
| Madison County | 494.4 | 1.1× larger | Compare |
| Perry County | 474.4 | about the same | Compare |
How big is St. Francois County compared with U.S. states?
St. Francois County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.3 times as much. Missouri’s county land could hold about 152 areas the size of St. Francois County.
Another way to picture it: the same land area would fill a square about 21.3 miles (34.2 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 St. Francois County?
St. Francois County has more land than 957 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 St. Francois County at #2,326 nationally by total area, 61 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 0.6%, compared with a national county-equivalent median of 1.2% — 0.6 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 St. Francois County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2264 | Madison County, Indiana | 451.9 | Compare |
| #2265 | St. Francois County, Missouri | 451.9 | This county |
| #2266 | La Crosse County, Wisconsin | 451.8 | 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 37.807260, -90.471947. 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: 1,170,380,024 m²; AWATER: 7,218,075 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 St. Francois County?
St. Francois County, Missouri has 451.9 square miles (1,170.4 km²) of land and 2.787 square miles of water, for a total area of 454.7 square miles. It ranks #2265 of 3,222 U.S. county equivalents by land area.
Is St. Francois County the largest county in Missouri?
No. St. Francois County ranks #96 of 115 in Missouri by land area. The largest is Texas County, with 1,177.3 square miles of land.
What counties border St. Francois County?
St. Francois County shares a land border with Ste. Genevieve County, Washington County, Madison County, Jefferson County, Iron County, and Perry County.
What is the population of St. Francois County?
The Census Bureau estimates St. Francois County had 67,809 residents on July 1, 2025, ranking #817 of 3,222 county equivalents. That is 150 people per square mile of land.
What is the county seat of St. Francois County?
The county seat of St. Francois County is Farmington.
What cities and towns are in St. Francois County?
St. Francois County has 8 incorporated places. The most populous five are Farmington city, Park Hills city, Bonne Terre city, Desloge city, and Bismarck city; 24,561 residents live outside any incorporated place.
Is St. Francois County part of a metropolitan area?
Yes. It is a central county of the Farmington, MO Micropolitan Statistical Area.
How many ZIP codes are in St. Francois County?
15 ZIP Code Tabulation Areas have land in St. Francois 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 St. Francois County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.3 times as much land.
How many acres of land are in St. Francois County?
The land measurement converts to approximately 289,207 acres. Including water, total area is approximately 290,991 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.