Irvine is a master-planned city in southern 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 f…Irvine is a master-planned city in southern 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 city had a population of 307,670 at the 2020 census.