Clay County area

Population and density of Clay County

The Census Bureau estimates that 265,032 people lived in Clay County on July 1, 2025. That ranks #281 of 3,222 county equivalents nationally and #6 of 115 in Missouri. Since the April 1, 2020 estimates base of 253,318, the population has grown by 11,714 (+4.6%), compared with +1.9% for Missouri as a whole.

With 397.7 square miles of land, that is 666 people per square mile (257 per km²), placing Clay County #265 nationally for density and #5 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 0.96 acres of land per resident.

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 Clay County

25 incorporated places lie at least partly in Clay County. Together they are home to 249,003 people (94%); the other 16,029 (6%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Kansas City city, with 144,263 residents in the county (the city extends into 3 other counties). The county seat, Liberty city, has 31,319 residents. Among places with at least 1,000 residents in 2020, North Kansas City city grew fastest since then (+25.7%).

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

Metropolitan area

Clay County is a central county of the Kansas City, MO-KS Metropolitan Statistical Area. Its 14 county equivalents have 2,270,682 residents on 7,256.8 square miles of land; Clay County accounts for 5.5% of the land and 11.7% of the residents. By combined land it ranks #25 of 393 metropolitan areas, and #31 by population. It belongs to the Kansas City-Overland Park-Kansas City, MO-KS Combined Statistical Area.

ZIP codes

23 ZIP Code Tabulation Areas have land in Clay County; 18 of them have most of their land inside the county, and the others mainly cover neighboring areas.

6402464048640606406264068640726407764089641166411764118641196415064151641556415664157641586416164165641666416764492

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 Clay County

Clay County shares a land border with 5 county equivalents, including 1 in Kansas. It has more land than 1 of them. The largest neighbor is Jackson County (604.7 mi²) and the smallest is Wyandotte County (151.6 mi²). Together with its neighbors, Clay County forms a block of 2,561.8 mi² of land, of which it holds 15.5%.

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

Clay County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.6 times as much. Missouri’s county land could hold about 173 areas the size of Clay County.

Another way to picture it: the same land area would fill a square about 19.9 miles (32.1 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 Clay County?

Clay County has more land than 686 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 Clay County at #2,554 nationally by total area, 18 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 2.7%, compared with a national county-equivalent median of 1.2% — 1.5 percentage points higher. 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 Clay County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.