About Orange County, California
Orange County is a coastal county in Southern California, between Los Angeles County to the north and San Diego County to the south. More than 3.1 million people live here, making it California’s third most populous county after Los Angeles and San Diego counties (California Department of Finance, 2026).
This page covers the basics: where Orange County is, how it came to be and a few key facts. Enjoy OC has been writing about Orange County since 2016, and for the cities themselves, our main guide has the details.
Looking for a city? See the list of all 34 Orange County cities, with an A–Z list, free downloads and a guide to the coast, north, central and south regions.
Where Is Orange County, California?
Orange County sits on the Pacific coast of Southern California. Los Angeles County lies to the north and northwest, San Bernardino County to the northeast, Riverside County to the east and San Diego County to the southeast, while the ocean forms the entire southwestern edge.
Downtown Los Angeles is roughly 25 to 30 miles from Anaheim, and San Diego is about 90 miles south of Santa Ana by freeway; drive times vary widely with traffic. John Wayne Airport (SNA) is the county’s main commercial airport.
The county seat is Santa Ana. Orange County has 34 incorporated cities plus unincorporated communities such as Ladera Ranch and Rossmoor; see the full city list for all of them.
Orange County Geography
Orange County covers about 793 square miles of land, or about 950 square miles including water (U.S. Census Bureau, 2024 Gazetteer). The landscape breaks into three broad parts: a flat, densely built coastal plain in the north and center, the San Joaquin Hills along the southern coast, and the Santa Ana Mountains along the eastern border with Riverside County.
The Santa Ana River crosses the county from the mountains to the ocean, reaching the Pacific between Huntington Beach and Newport Beach. Six cities sit directly on the coast, with beaches that range from long, wide sand to rocky coves and tidepools.
The climate is mild for much of the year, with warm, dry summers and cooler, wetter winters. Late spring often brings cloudy coastal mornings, locally called “May Gray” and “June Gloom.” Our best time to visit Orange County guide breaks the seasons down month by month.
A Short History of Orange County
Long before Spanish settlement, this land was home to Native peoples, including the Acjachemen (Juaneño) in the south and the Tongva in the north. Spanish missionaries founded Mission San Juan Capistrano in 1776, and under Spanish and then Mexican rule much of the land was divided into large cattle ranchos.
In 1857, German settlers founded Anaheim as a wine-growing colony. Farming towns grew up around it, and in 1889 the area split from Los Angeles County to become Orange County. Anaheim, Santa Ana and Orange were its first incorporated cities.
Citrus groves, especially oranges, shaped the county’s economy and image for decades, and oil fields in the north added to the boom. Early in the 1900s, Pacific Electric “Red Car” trains linked Los Angeles to the coast, reaching Huntington Beach in 1904 and Newport Beach the following year. In Old Towne Orange, the historic downtown still has brick storefronts around its Plaza.
Tourism took off in the 20th century. Walter Knott began growing berries in Buena Park in the 1920s, and Cordelia Knott’s fried chicken dinners, first served in 1934, grew into today’s Knott’s Berry Farm, which bills itself as America’s first theme park. Disneyland opened in Anaheim in 1955; Walt Disney’s original garage is now at the Stanley Ranch Museum in Garden Grove.
After World War II, orange groves gave way to suburbs, freeways and master-planned communities such as Irvine, which grew around UC Irvine after the campus opened in 1965. Many South County communities did not become cities until the late 1980s or later; the newest, Aliso Viejo, incorporated in 2001.
Want to see this history in person? Our Orange County historic sites guide covers missions, historic downtowns and museums across the county.
Orange County Quick Facts
- Formed: 1889, from part of Los Angeles County
- County seat: Santa Ana
- Population: 3,163,696 (California Department of Finance, January 1, 2026)
- Rank in California: 3rd most populous county (DOF, 2026)
- Land area: about 793 square miles; about 950 square miles including water (U.S. Census Bureau, 2024 Gazetteer)
- Cities: 34 incorporated cities (see the full list)
- Most populous city: Anaheim; largest by land area: Irvine
- Coastline: 6 coastal cities, from Seal Beach to San Clemente
- Main airport: John Wayne Airport (SNA)
- Universities include: UC Irvine, Cal State Fullerton and Chapman University
For population by city, see Orange County population by city. Other quick references: ZIP codes, maps and city mottos.
What Orange County Is Known For
Most people know Orange County for its beaches and surf spots like the Wedge, plus Disneyland and Knott’s Berry Farm. There is also plenty of open space, from Crystal Cove State Park to canyon hikes like Black Star Canyon, and shopping at South Coast Plaza, Fashion Island, Pacific City and the outlet malls.
Every part of the county feels a little different, and our regional city guide breaks it down region by region. Ready to plan? Browse things to do in Orange County, the OC events calendar and what to do this weekend.
Orange County FAQ
Is Orange County part of Los Angeles?
No. Orange County has been its own county since 1889, when it separated from Los Angeles County. The two counties border each other, and many people commute between them.
What is the county seat of Orange County?
Santa Ana.
How many people live in Orange County?
About 3.16 million, according to the California Department of Finance estimate for January 1, 2026.
How many cities are in Orange County?
There are 34 incorporated cities. See our list of Orange County cities for all of them, A to Z and by region.
How far is Orange County from Los Angeles and San Diego?
Anaheim is roughly 25 to 30 miles from downtown Los Angeles, and Santa Ana is about 90 miles from San Diego by freeway. Actual drive times depend heavily on traffic.
Official resources: OC Parks · California State Parks · County of Orange services · California Department of Finance population estimates · U.S. Census Bureau Gazetteer files
