East Rancho Dominguez, also known as East Compton, is an unincorporated community and census-designated place located in southern Los Angeles County, California. The population was 15,135 at the 2010 census, up from 9,286 at the 2000 census. East Rancho Dominguez is an accepted city name according to the USPS, and shares the 90221 ZIP Code with Compton. East Rancho Dominguez is an unincorporated enclave surrounded by Compton within five blocks east and west of Atlantic Ave.