Irvine is an affluent city in Orange County, California, United States. It is a planned city; the Irvine Company started developing the area in the 1960s. Formally incorporated on December 28, 1971, the 66-square-mile city had a population of 212,375 as of the 2010 census; in 2016 the city's population was 258,386. A number of corporations, particularly in the technology and semiconductor sectors, have their national or international headquarters in Irvine.