El Centro is the county seat of Imperial County, California, United States and the largest city in the Imperial Valley, the region east of San Diego. It is also the largest U.S. city to lie entirely below sea level. It is the core urban area and principal city of the 'El Centro, California Metropolitan Statistical Area' which encompasses all of Imperial County. It is home to retail, transportation, wholesale, and agricultural industries. El Centro is Spanish, and means the center. The city's population was 37,835 at the 2000 census. El Centro apartments for rent comparison page shows most up to date rent information on El Centro apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.