County outline
Where Ventura County is located
Area breakdown
Land accounts for 83.4% of Ventura County’s measured area and water for 16.6%. Its combined area converts to 5,715 square kilometers or approximately 1,412,198 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 1,840.78 | 4,767.598 | 1,178,099.2 |
| Water | 365.779 | 947.363 | 234,098.6 |
| Total | 2,206.559 | 5,714.962 | 1,412,197.8 |
How Ventura County compares
By original Census land area, Ventura County ranks #26 of 58 in California and #318 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.199 times the California county-equivalent median of 1,535.7 square miles. It accounts for 1.2% of the combined county land area in the state.
See the complete California ranking · What counts as a county equivalent?
Population and density of Ventura County
The Census Bureau estimates that 830,851 people lived in Ventura County on July 1, 2025. That ranks #77 of 3,222 county equivalents nationally and #12 of 58 in California. Since the April 1, 2020 estimates base of 844,358, the population has declined by 13,507 (−1.6%), compared with −0.5% for California as a whole.
With 1,840.8 square miles of land, that is 451 people per square mile (174 per km²), placing Ventura County #374 nationally for density and #14 in California. The median county equivalent has 47 people per square mile; the California median is 112. Put another way, there are about 1.4 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 843,793 | 839,956 | 834,675 | 832,071 | 833,431 | 830,851 |
| Change | — | −3,837 | −5,281 | −2,604 | +1,360 | −2,580 |
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 Ventura County
10 incorporated places lie at least partly in Ventura County. Together they are home to 737,503 people (88.8%); the other 93,348 (11.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Oxnard city, with 199,651 residents in the county. By land, Thousand Oaks city is the largest at 55.3 mi². Among places with at least 1,000 residents in 2020, Santa Paula city grew fastest since then (+3.6%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Oxnard city | 199,651 | −1.2% | 26.5 |
| Simi Valley city | 124,861 | −1.2% | 41.5 |
| Thousand Oaks city | 122,230 | −3.7% | 55.3 |
| San Buenaventura (Ventura) city | 109,914 | −0.8% | 21.9 |
| Camarillo city | 68,652 | −3% | 19.7 |
| Moorpark city | 35,023 | −3.5% | 12.3 |
| Santa Paula city | 31,774 | +3.6% | 5.53 |
| Port Hueneme city | 20,987 | −4.5% | 4.415 |
| Fillmore city | 16,937 | +3.1% | 3.303 |
| Ojai city | 7,474 | −1.9% | 4.356 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Ventura County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Ventura County is a central county of the Oxnard-Thousand Oaks-Ventura, CA Metropolitan Statistical Area. Ventura County is the area’s only county equivalent, so the metro area has the same 1,840.8 square miles of land. By combined land it ranks #170 of 393 metropolitan areas, and #76 by population. It belongs to the Los Angeles-Long Beach, CA Combined Statistical Area.
ZIP codes
34 ZIP Code Tabulation Areas have land in Ventura County; 29 of them have most of their land inside the county, and the others mainly cover neighboring areas.
90265913049130791311913209136091361913629137793001930039300493010930129301393015930219302293023930309303393035930369304093041930429304393060930639306493065930669322593252
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 Ventura County
Ventura County shares a land border with 3 county equivalents. Each of them has more land than Ventura County. The largest neighbor is Kern County (8,134.7 mi²) and the smallest is Santa Barbara County (2,733.9 mi²). Together with its neighbors, Ventura County forms a block of 16,769.7 mi² of land, of which it holds 11%.
| Bordering county equivalent | Land mi² | Size vs. Ventura | Compare |
|---|---|---|---|
| Kern County | 8,134.7 | 4.4× larger | Compare |
| Los Angeles County | 4,060.3 | 2.2× larger | Compare |
| Santa Barbara County | 2,733.9 | 1.5× larger | Compare |
How big is Ventura County compared with U.S. states?
Ventura County has more land than 1 of the 50 states. It is about 1.8 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.1 times as much land (1,948.6 mi²). California’s county land could hold about 85 areas the size of Ventura County.
Another way to picture it: the same land area would fill a square about 42.9 miles (69 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 Ventura County?
Ventura County has more land than 2,904 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 Ventura County at #283 nationally by total area, 35 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 16.6%, compared with a national county-equivalent median of 1.2% — 15.4 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 Ventura County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #317 | Greenlee County, Arizona | 1,842.8 | Compare |
| #318 | Ventura County, California | 1,840.8 | This county |
| #319 | Logan County, Colorado | 1,838.6 | Compare |
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.
Representative coordinates
The Census internal point is 34.359007, -119.132901. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 4,767,597,083 m²; AWATER: 947,364,152 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Ventura County?
Ventura County, California has 1,840.8 square miles (4,767.6 km²) of land and 365.8 square miles of water, for a total area of 2,206.6 square miles. It ranks #318 of 3,222 U.S. county equivalents by land area.
Is Ventura County the largest county in California?
No. Ventura County ranks #26 of 58 in California by land area. The largest is San Bernardino County, with 20,068.4 square miles of land.
What counties border Ventura County?
Ventura County shares a land border with Los Angeles County, Santa Barbara County, and Kern County.
What is the population of Ventura County?
The Census Bureau estimates Ventura County had 830,851 residents on July 1, 2025, ranking #77 of 3,222 county equivalents. That is 451 people per square mile of land.
What is the county seat of Ventura County?
The county seat of Ventura County is Ventura.
What cities and towns are in Ventura County?
Ventura County has 10 incorporated places. The most populous five are Oxnard city, Simi Valley city, Thousand Oaks city, San Buenaventura (Ventura) city, and Camarillo city; 93,348 residents live outside any incorporated place.
Is Ventura County part of a metropolitan area?
Yes. It is a central county of the Oxnard-Thousand Oaks-Ventura, CA Metropolitan Statistical Area.
How many ZIP codes are in Ventura County?
34 ZIP Code Tabulation Areas have land in Ventura County, and 29 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Ventura County compare with U.S. states?
It has more land than 1 of the 50 states, including Rhode Island (1,033.9 square miles of land).
How many acres of land are in Ventura County?
The land measurement converts to approximately 1,178,099 acres. Including water, total area is approximately 1,412,198 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.