Irvine is the largest city and a master-planned city in central Orange County, California, United States, in the Los Angeles metropolitan area. The Irvine Company started developing the area in the 1960s and the city was formally incorporated on December 28, 1971. The 66-square-mile (170 km2) city had a population of 307,670 at the 2020 census; it is the 63rd most populous city in the United States.

Orange County is a county located in the Los Angeles metropolitan area in Southern California, United States. As of the 2020 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 American states and Washington, D.C. Although largely 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 exceeding 300,000. Santa Ana is also the county seat. Six cities in Orange County are on the Pacific coast: Seal Beach, Huntington Beach, Newport Beach, Laguna Beach, Dana Point, and San Clemente.