Santa Ana /ˌsæntə ˈænə/ is the county seat and second most populous city in Orange County, California. With a population of 329,427, as of the 2011 census, Santa Ana is the 57th most-populous city in the United States.
Founded in 1869, Santa Ana is located in Southern California adjacent to the Santa Ana River, 10 miles (16 km) away from the California coast. The city is part of the Greater Los Angeles Area which, according to the U.S. Census Bureau, is the second largest metropolitan area in the U.S., with almost eighteen million people. According to the 2000 U.S. Census, of U.S. cities with more than 300,000 people, Santa Ana is the 4th-most densely populated behind only New York City, San Francisco, and Chicago, and slightly denser than Boston.
Santa Ana lends its name to the Santa Ana Freeway (I-5), which runs through the city. It also shares its name with the nearby Santa Ana Mountains, and the Santa Ana winds, which have historically fueled seasonal wildfires throughout Southern California. The current Office of Management and Budget (OMB) metropolitan designation for the Orange County Area is Santa Ana–Anaheim–Irvine, California.