Flag of Orange County, California, USA Sticker

Orange County (officially the County of Orange; often initialized O.C.) is a county located in the Greater Los Angeles area in Southern California, United States. As of the 2020 United States census, the population was 3,186,989, making it the third most populous county in California, the sixth most populous in the United States, and more populous than 19 U.S. states and Washington, D.C. Although mostly suburban, it is the second most densely populated county in the state behind San Francisco County. The county's three most populous cities are Anaheim, Santa Ana and Irvine, each of which has a population surpassing 300,000. Santa Ana is also the county seat. Six cities in Orange County lie along the Pacific Coast: Seal Beach, Huntington Beach, Newport Beach, Laguna Beach, Dana Point and San Clemente. Orange County is included in the Los Angeles–Long Beach–Anaheim Metropolitan Statistical Area. The county has 34 incorporated cities. Older cities such as Tustin, Santa Ana, Anaheim, Orange and Fullerton have traditional downtowns dating back to the 19th century, while newer commercial development or "edge cities" stretch along the Interstate 5 (Santa Ana) Freeway between Disneyland and Santa Ana and between South Coast Plaza and the Irvine Business Complex and cluster at Irvine Spectrum. The county is a tourist center, with attractions such as Disneyland Resort, Knott's Berry Farm, Mission San Juan Capistrano, Huntington Beach Pier, the Richard Nixon Presidential Library and Museum, Orange County Zoo, Modjeska House, Segerstrom Center for the Arts, Yost Theater, Bowers Museum, Balboa Island, Angel Stadium, Downtown Santa Ana, Crystal Cove Historic District, Honda Center, the Old Orange County Courthouse, Orange County Fair, the Irvine Ranch Natural Landmarks, Heritage Hills Historic Park, Ocean Institute and several popular beaches along its more than 40 mi (64 km) of coastline. It is also home to a major research university, the University of California, Irvine (UCI), along with a number of other notable colleges and universities such as Chapman University and Cal State Fullerton.