Orange County area

Population and density of Orange County

The Census Bureau estimates that 3,149,507 people lived in Orange County on July 1, 2025. That ranks #6 of 3,222 county equivalents nationally and #3 of 58 in California. Since the April 1, 2020 estimates base of 3,187,279, the population has declined by 37,772 (−1.2%), compared with −0.5% for California as a whole.

With 793.2 square miles of land, that is 3,970 people per square mile (1,533 per km²), placing Orange County #30 nationally for density and #2 in California. The median county equivalent has 47 people per square mile; the California median is 112. Put another way, there are about 0.161 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 Orange County

34 incorporated places lie at least partly in Orange County. Together they are home to 3,018,581 people (95.8%); the other 130,926 (4.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Anaheim city, with 341,008 residents in the county. The county seat, Santa Ana city, has 315,586 residents. By land, Irvine city is the largest at 65.6 mi². Among places with at least 1,000 residents in 2020, Stanton city grew fastest since then (+5.8%).

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

Metropolitan area

Orange County is a central county of the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area, in the Anaheim-Santa Ana-Irvine, CA metropolitan division. Its 2 county equivalents have 12,844,441 residents on 4,853.5 square miles of land; Orange County accounts for 16.3% of the land and 24.5% of the residents. By combined land it ranks #53 of 393 metropolitan areas, and #2 by population. It belongs to the Los Angeles-Long Beach, CA Combined Statistical Area.

ZIP codes

92 ZIP Code Tabulation Areas have land in Orange County; 88 of them have most of their land inside the county, and the others mainly cover neighboring areas.

9062090621906239063090631906389068090716907209074090742907439253092602926039260492606926109261292614926179261892620926249262592626926279262992630926379264692647926489264992651926539265592656926579266092661926629266392672926739267592676926779267892679926839268892691926929269492697927019270392704927059270692707927089278092782928019280292804928059280692807928089282192823928319283292833928359284092841928439284492845928619286592866928679286892869928709288692887

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 Orange County

Orange County shares a land border with 4 county equivalents. Each of them has more land than Orange County. The largest neighbor is San Bernardino County (20,068.4 mi²) and the smallest is Los Angeles County (4,060.3 mi²). Together with its neighbors, Orange County forms a block of 36,341.9 mi² of land, of which it holds 2.2%.

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

Orange County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.3 times as much. California’s county land could hold about 196 areas the size of Orange County.

Another way to picture it: the same land area would fill a square about 28.2 miles (45.3 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 Orange County?

Orange County has more land than 2,141 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 Orange County at #846 nationally by total area, 235 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 16.5%, compared with a national county-equivalent median of 1.2% — 15.3 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 Orange 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.