Irvine is a master-planned city in 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 212,375 as of the 2010 census; in 2018 the California Department of Finance estimated the city's population at 276,176.