County outline
Where Pettis County is located
Area breakdown
Land accounts for 99.4% of Pettis County’s measured area and water for 0.6%. Its combined area converts to 1,777.5 square kilometers or approximately 439,219 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 682.237 | 1,766.986 | 436,631.7 |
| Water | 4.042 | 10.469 | 2,586.9 |
| Total | 686.279 | 1,777.454 | 439,218.6 |
How Pettis County compares
By original Census land area, Pettis County ranks #32 of 115 in Missouri and #1373 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.152 times the Missouri county-equivalent median of 592 square miles. It accounts for 1% of the combined county land area in the state.
See the complete Missouri ranking · What counts as a county equivalent?
Population and density of Pettis County
The Census Bureau estimates that 44,254 people lived in Pettis County on July 1, 2025. That ranks #1,134 of 3,222 county equivalents nationally and #25 of 115 in Missouri. Since the April 1, 2020 estimates base of 42,987, the population has grown by 1,267 (+2.9%), compared with +1.9% for Missouri as a whole.
With 682.2 square miles of land, that is 65 people per square mile (25 per km²), placing Pettis County #1,324 nationally for density and #30 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 9.9 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 43,011 | 43,237 | 43,376 | 43,611 | 43,894 | 44,254 |
| Change | — | +226 | +139 | +235 | +283 | +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 Pettis County
8 incorporated places lie at least partly in Pettis County. Together they are home to 25,213 people (57%); the other 19,041 (43%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Sedalia city, with 22,621 residents in the county. Among places with at least 1,000 residents in 2020, Sedalia city grew fastest since then (+4.1%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Sedalia cityCounty seat | 22,621 | +4.1% | 15 |
| La Monte city | 1,018 | +1.3% | 1.085 |
| Green Ridge city | 601 | +28.1% | 0.429 |
| Smithton city | 508 | +0.6% | 0.301 |
| Houstonia city | 201 | +1% | 0.198 |
| Hughesville village | 151 | +0.7% | 0.116 |
| Windsor cityAlso in 1 other county | 111 | +3.7% | 2.419 |
| Ionia townAlso in 1 other county | 2 | 0% | 0.148 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Pettis County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Pettis County is a central county of the Sedalia, MO Micropolitan Statistical Area. Pettis County is the area’s only county equivalent, so the micro area has the same 682.2 square miles of land. By combined land it ranks #316 of 542 micropolitan areas, and #283 by population.
ZIP codes
15 ZIP Code Tabulation Areas have land in Pettis County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
653016532565332653336533465335653366533765340653456534765348653506535165360
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 Pettis County
Pettis County shares a land border with 7 county equivalents. It has more land than 3 of them. The largest neighbor is Johnson County (829.3 mi²) and the smallest is Cooper County (564.7 mi²). Together with its neighbors, Pettis County forms a block of 5,458.6 mi² of land, of which it holds 12.5%.
| Bordering county equivalent | Land mi² | Size vs. Pettis | Compare |
|---|---|---|---|
| Johnson County | 829.3 | 1.2× larger | Compare |
| Saline County | 755.5 | 1.1× larger | Compare |
| Benton County | 704 | about the same | Compare |
| Henry County | 696.9 | about the same | Compare |
| Lafayette County | 628.3 | 1.1× smaller | Compare |
| Morgan County | 597.5 | 1.1× smaller | Compare |
| Cooper County | 564.7 | 1.2× smaller | Compare |
How big is Pettis County compared with U.S. states?
Pettis County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.5 times as much. Missouri’s county land could hold about 101 areas the size of Pettis County.
Another way to picture it: the same land area would fill a square about 26.1 miles (42 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 Pettis County?
Pettis County has more land than 1,849 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 Pettis County at #1,476 nationally by total area, 103 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 Pettis County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #1372 | Licking County, Ohio | 682.4 | Compare |
| #1373 | Pettis County, Missouri | 682.2 | This county |
| #1374 | Wright County, Missouri | 681.8 | 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 38.724013, -93.292696. 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: 1,766,986,596 m²; AWATER: 10,468,067 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 Pettis County?
Pettis County, Missouri has 682.2 square miles (1,767 km²) of land and 4.042 square miles of water, for a total area of 686.3 square miles. It ranks #1373 of 3,222 U.S. county equivalents by land area.
Is Pettis County the largest county in Missouri?
No. Pettis County ranks #32 of 115 in Missouri by land area. The largest is Texas County, with 1,177.3 square miles of land.
What counties border Pettis County?
Pettis County shares a land border with Johnson County, Benton County, Saline County, Cooper County, Morgan County, Henry County, and Lafayette County.
What is the population of Pettis County?
The Census Bureau estimates Pettis County had 44,254 residents on July 1, 2025, ranking #1,134 of 3,222 county equivalents. That is 65 people per square mile of land.
What is the county seat of Pettis County?
The county seat of Pettis County is Sedalia.
What cities and towns are in Pettis County?
Pettis County has 8 incorporated places. The most populous five are Sedalia city, La Monte city, Green Ridge city, Smithton city, and Houstonia city; 19,041 residents live outside any incorporated place.
Is Pettis County part of a metropolitan area?
Yes. It is a central county of the Sedalia, MO Micropolitan Statistical Area.
How many ZIP codes are in Pettis County?
15 ZIP Code Tabulation Areas have land in Pettis County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Pettis County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1.5 times as much land.
How many acres of land are in Pettis County?
The land measurement converts to approximately 436,632 acres. Including water, total area is approximately 439,219 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.