Cass County area

Population and density of Cass County

The Census Bureau estimates that 115,859 people lived in Cass County on July 1, 2025. That ranks #561 of 3,222 county equivalents nationally and #10 of 115 in Missouri. Since the April 1, 2020 estimates base of 107,824, the population has grown by 8,035 (+7.5%), compared with +1.9% for Missouri as a whole.

With 696.6 square miles of land, that is 166 people per square mile (64 per km²), placing Cass County #721 nationally for density and #14 in Missouri. The median county equivalent has 47 people per square mile; the Missouri median is 31. Put another way, there are about 3.8 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 Cass County

23 incorporated places lie at least partly in Cass County. Together they are home to 90,555 people (78.2%); the other 25,304 (21.8%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Raymore city, with 26,633 residents in the county. The county seat, Harrisonville city, has 10,040 residents. By land, Kansas City city is the largest at 314.5 mi² across all its counties. Among places with at least 1,000 residents in 2020, Lake Winnebago city grew fastest since then (+30%).

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

Metropolitan area

Cass 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; Cass County accounts for 9.6% of the land and 5.1% 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

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

640126403464040640616407864080640826408364090641476470164725647346473964742647436474664747

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 Cass County

Cass County shares a land border with 6 county equivalents, including 2 in Kansas. It has more land than 3 of them. The largest neighbor is Bates County (836.7 mi²) and the smallest is Johnson County (473.6 mi²). Together with its neighbors, Cass County forms a block of 4,713.7 mi² of land, of which it holds 14.8%.

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

Cass 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 99 areas the size of Cass County.

Another way to picture it: the same land area would fill a square about 26.4 miles (42.5 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 Cass County?

Cass County has more land than 1,889 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 Cass County at #1,431 nationally by total area, 98 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 0.8%, compared with a national county-equivalent median of 1.2% — 0.3 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 Cass 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.