Ogle County area

Population and density of Ogle County

The Census Bureau estimates that 51,399 people lived in Ogle County on July 1, 2025. That ranks #1,008 of 3,222 county equivalents nationally and #28 of 102 in Illinois. Since the April 1, 2020 estimates base of 51,850, the population has declined by 451 (−0.9%), compared with −0.8% for Illinois as a whole.

With 758.7 square miles of land, that is 68 people per square mile (26 per km²), placing Ogle County #1,283 nationally for density and #35 in Illinois. The median county equivalent has 47 people per square mile; the Illinois median is 44. Put another way, there are about 9.4 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 Ogle County

14 incorporated places lie at least partly in Ogle County. Together they are home to 29,638 people (57.7%); the other 21,761 (42.3%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Rochelle city, with 9,498 residents in the county (the city extends into 1 other county). The county seat, Oregon city, has 3,573 residents. By land, Rockford city is the largest at 65.6 mi² across all its counties. Among places with at least 1,000 residents in 2020, Davis Junction village grew fastest since then (+2.3%).

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

Metropolitan area

Ogle County is a central county of the Rochelle, IL Micropolitan Statistical Area. Ogle County is the area’s only county equivalent, so the micro area has the same 758.7 square miles of land. By combined land it ranks #283 of 542 micropolitan areas, and #214 by population. It belongs to the Rockford-Freeport-Rochelle, IL Combined Statistical Area.

ZIP codes

27 ZIP Code Tabulation Areas have land in Ogle County; 17 of them have most of their land inside the county, and the others mainly cover neighboring areas.

601136012960146610066100761010610156102061021610306103161039610436104761049610516105261054610616106461068610786108461088610916110261109

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 Ogle County

Ogle County shares a land border with 6 county equivalents. It has more land than every one of them. The largest neighbor is Lee County (724.8 mi²) and the smallest is Carroll County (445.4 mi²). Together with its neighbors, Ogle County forms a block of 4,321.6 mi² of land, of which it holds 17.6%.

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

Ogle County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.4 times as much. Illinois’s county land could hold about 73 areas the size of Ogle County.

Another way to picture it: the same land area would fill a square about 27.5 miles (44.3 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 Ogle County?

Ogle County has more land than 2,068 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 Ogle County at #1,258 nationally by total area, 104 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% — 0.5 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 Ogle 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.