Members of the Tongva, Juaneño, and Luiseño Native American groups long inhabited the area. After the 1769 expedition of Gaspar de Portolà, a Spanish expedition led by Junipero Serra named the area Valle de Santa Ana (Valley of Saint Anne). On November 1, 1776, Mission San Juan Capistrano became the area’s first permanent European settlement.
According to the U.S. Census Bureau, the county has a total area of 948 square miles (2,460 km2), of which 791 square miles (2,050 km2) is land and 157 square miles (410 km2) (16.6%) is water. It is the smallest county in Southern California. The average annual temperature is about 68 °F (20 °C).
Orange County is bordered on the southwest by the Pacific Ocean, on the north by Los Angeles County, on the northeast by San Bernardino County and Riverside County, and on the southeast by San Diego County.
The 2010 United States Census reported that Orange County had a population of 3,010,232. The racial makeup of Orange County was 1,830,758 (60.8%) White (44.0% non-Hispanic white), 50,744 (1.7%) African American, 18,132 (0.6%) Native American, 537,804 (17.9%) Asian, 9,354 (0.3%) Pacific Islander, 435,641 (14.5%) from other races, and 127,799 (4.2%) from two or more races. Hispanic or Latino of any race were 1,012,973 persons (33.7%).
The Hispanic and Latino population is predominantly of Mexican origin; this group accounts for 28.5% of the county’s population, followed by Salvadorans (0.8%), Guatemalans (0.5%), Puerto Ricans (0.4%), Cubans (0.3%), Colombians (0.3%), and Peruvians (0.3%).
Orange County is the headquarters of many Fortune 500 companies including Ingram Micro (#69) and First American Corporation (#312) in Santa Ana, Broadcom (#343) in Irvine, Western Digital (#439) in Lake Forest and Pacific Life (#452) in Newport Beach. Irvine is the home of numerous start-up companies and also is the home of Fortune 1000 headquarters for Allergan, Edwards Lifesciences, Epicor, Standard Pacific and Sun Healthcare Group.
Orange County is a charter county of California; its seat is Santa Ana. Its legislative and executive authority is vested in the five-member Orange County Board of Supervisors. Each Supervisor is popularly elected from a regional district, and together the board oversees the activities of the county’s agencies and departments and sets policy on development, public improvements, and county services. At the beginning of each calendar year, the Supervisors select a Chair and Vice Chair amongst themselves.
Total: 66.454 sq mi
Land: 66.106 sq mi
Water: 0.348 sq mi
Density: 3,900/sq mi