Riverside is a city in, and the county seat of, Riverside County, California, United States, located in the Inland Empire metropolitan area. It is named for its location beside the Santa Ana River. It is the most populous city in the Inland Empire and in Riverside County, and is located about 55 mi east of downtown Los Angeles. It is also part of the Greater Los Angeles area. Riverside is the 58th most populous city in the United States and 12th most populous city in California. As of the 2010 Census, Riverside had a population of 303,871.