Oconto County area

Population and density of Oconto County

The Census Bureau estimates that 40,195 people lived in Oconto County on July 1, 2025. That ranks #1,206 of 3,222 county equivalents nationally and #38 of 72 in Wisconsin. Since the April 1, 2020 estimates base of 38,967, the population has grown by 1,228 (+3.2%), compared with +1.3% for Wisconsin as a whole.

With 997.5 square miles of land, that is 40 people per square mile (16 per km²), placing Oconto County #1,747 nationally for density and #41 in Wisconsin. The median county equivalent has 47 people per square mile; the Wisconsin median is 51. Put another way, there are about 16 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 Oconto County

Oconto County is divided into 29 cities and towns. In Wisconsin, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Little Suamico town, with 5,794 residents (14.4% of the county). The largest by land is Mountain town, at 71.7 mi², or 7.2% of the county’s land. The county seat, Oconto city, has 4,640 residents. Among those with at least 1,000 residents in 2020, Chase town grew fastest since then (+6.2%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Oconto County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Oconto County is an outlying county of the Green Bay, WI Metropolitan Statistical Area. Its 3 county equivalents have 336,756 residents on 1,870 square miles of land; Oconto County accounts for 53.3% of the land and 11.9% of the residents. By combined land it ranks #167 of 393 metropolitan areas, and #162 by population. It belongs to the Green Bay-Shawano, WI Combined Statistical Area.

ZIP codes

19 ZIP Code Tabulation Areas have land in Oconto County; 12 of them have most of their land inside the county, and the others mainly cover neighboring areas.

54101541115411254114541245413754138541395414154149541535415454157541615416254171541745417554491

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 Oconto County

Oconto County shares a land border with 6 county equivalents. It has more land than 4 of them. The largest neighbor is Marinette County (1,399.5 mi²) and the smallest is Menominee County (357.6 mi²). Together with its neighbors, Oconto County forms a block of 6,062.8 mi² of land, of which it holds 16.5%.

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

Oconto 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 times as much. Wisconsin’s county land could hold about 54 areas the size of Oconto County.

Another way to picture it: the same land area would fill a square about 31.6 miles (50.8 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 Oconto County?

Oconto County has more land than 2,537 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 Oconto County at #626 nationally by total area, 59 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 13.2%, compared with a national county-equivalent median of 1.2% — 12 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 Oconto 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.