Dallas County area

Dallas County, Missouri covers 542.8 square miles: 541 square miles of land and 1.895 square miles of water. Its county seat is Buffalo. An estimated 18,025 people lived there in 2025.

Official Census measurements · GEOID 290592026 Gazetteer · retrieved September 27, 2026
Land area541 mi²
Water area1.895 mi²
Population (2025)18,025
People per mi²33

County outline

Generalized outline of Dallas County, Missouri
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Dallas County is located

Dallas County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 99.7% of Dallas County’s measured area and water for 0.3%. Its combined area converts to 1,406 square kilometers or approximately 347,421 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land540.9511,401.057346,208.6
Water1.8954.9081,212.8
Total542.8461,405.965347,421.4

How Dallas County compares

By original Census land area, Dallas County ranks #70 of 115 in Missouri and #1931 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.914 times the Missouri county-equivalent median of 592 square miles. It accounts for 0.8% of the combined county land area in the state.

See the complete Missouri ranking · What counts as a county equivalent?

Population and density of Dallas County

The Census Bureau estimates that 18,025 people lived in Dallas County on July 1, 2025. That ranks #1,999 of 3,222 county equivalents nationally and #61 of 115 in Missouri. Since the April 1, 2020 estimates base of 17,071, the population has grown by 954 (+5.6%), compared with +1.9% for Missouri as a whole.

With 541 square miles of land, that is 33 people per square mile (13 per km²), placing Dallas County #1,910 nationally for density and #53 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 19 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate17,13317,34817,60217,76517,85818,025
Change—+215+254+163+93+167

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 Dallas County

3 incorporated places lie at least partly in Dallas County. Together they are home to 4,101 people (22.8%); the other 13,924 (77.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Buffalo city, with 3,550 residents in the county.

Incorporated placePopulation 2025Since 2020Land mi²
Buffalo cityCounty seat3,550+7.9%3.003
Urbana city411+4.6%0.849
Louisburg village140+3.7%0.465

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Dallas County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Dallas County is an outlying county of the Springfield, MO Metropolitan Statistical Area. Its 5 county equivalents have 500,694 residents on 3,007 square miles of land; Dallas County accounts for 18% of the land and 3.6% of the residents. By combined land it ranks #98 of 393 metropolitan areas, and #112 by population.

County equivalentPopulation 2025Land mi²
Greene County309,286675.3
Christian County96,725562.6
Webster County43,054592.6
Polk County33,604635.5
Dallas County18,025541

ZIP codes

13 ZIP Code Tabulation Areas have land in Dallas County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.

65463655366559065622656326564465648656856572265764657676578365786

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 Dallas County

Dallas County shares a land border with 6 county equivalents. It has more land than 1 of them. The largest neighbor is Laclede County (764.7 mi²) and the smallest is Hickory County (398.8 mi²). Together with its neighbors, Dallas County forms a block of 4,263.7 mi² of land, of which it holds 12.7%.

Map of Dallas County and the 6 county equivalents that border it Laclede County, Missouri: 764.7 mi² landPolk County, Missouri: 635.5 mi² landWebster County, Missouri: 592.6 mi² landHickory County, Missouri: 398.8 mi² landCamden County, Missouri: 655.8 mi² landGreene County, Missouri: 675.3 mi² land
Dallas County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. DallasCompare
Laclede County764.71.4× largerCompare
Greene County675.31.2× largerCompare
Camden County655.81.2× largerCompare
Polk County635.51.2× largerCompare
Webster County592.61.1× largerCompare
Hickory County398.81.4× smallerCompare

How big is Dallas County compared with U.S. states?

Dallas County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.9 times as much. Missouri’s county land could hold about 127 areas the size of Dallas County.

Land area: Dallas County and the closest-sized states
Dallas County541 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23.3 miles (37.4 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 Dallas County?

Dallas County has more land than 1,291 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Dallas County541 mi²
Missouri median592 mi²
National median604.5 mi²

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 Dallas County at #2,032 nationally by total area, 101 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 0.3%, compared with a national county-equivalent median of 1.2% — 0.8 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 Dallas County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1930Botetourt County, Virginia541.3Compare
#1931Dallas County, Missouri541This county
#1932Dorchester County, Maryland540.8Compare

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 37.683582, -93.033815. 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: 1,401,057,563 m²; AWATER: 4,909,174 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Dallas County?

Dallas County, Missouri has 541 square miles (1,401.1 km²) of land and 1.895 square miles of water, for a total area of 542.8 square miles. It ranks #1931 of 3,222 U.S. county equivalents by land area.

Is Dallas County the largest county in Missouri?

No. Dallas County ranks #70 of 115 in Missouri by land area. The largest is Texas County, with 1,177.3 square miles of land.

What counties border Dallas County?

Dallas County shares a land border with Laclede County, Polk County, Webster County, Hickory County, Camden County, and Greene County.

What is the population of Dallas County?

The Census Bureau estimates Dallas County had 18,025 residents on July 1, 2025, ranking #1,999 of 3,222 county equivalents. That is 33 people per square mile of land.

What is the county seat of Dallas County?

The county seat of Dallas County is Buffalo.

What cities and towns are in Dallas County?

Dallas County has 3 incorporated places. The most populous are Buffalo city, Urbana city, and Louisburg village; 13,924 residents live outside any incorporated place.

Is Dallas County part of a metropolitan area?

Yes. It is an outlying county of the Springfield, MO Metropolitan Statistical Area, which has 5 county equivalents and 500,694 residents.

How many ZIP codes are in Dallas County?

13 ZIP Code Tabulation Areas have land in Dallas 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 Dallas County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.9 times as much land.

How many acres of land are in Dallas County?

The land measurement converts to approximately 346,209 acres. Including water, total area is approximately 347,421 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.

Cite this county

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