Irvine is a planned city in central Orange County, California, United States, in the Los Angeles metropolitan area. It was named in 1888 for the landowner James Irvine. The Irvine Company started developing the area in the 1960s. The city was formally incorporated on December 28, 1971. The 66-square-mile (170 km2) city had a population of 318,629 as of June 2025. As of 2025, it is the second most populous city in Orange County, fifth most in the Greater Los Angeles region, and 63rd most in the United States.