Ontario is a city located in south west San Bernardino County, California, United States, 35 miles east of downtown Los Angeles. Located in the western part of the Inland Empire region, it lies just east of the Los Angeles county line and is part of the Greater Los Angeles Area. Wikipedia

Orange County is a county in the U.S. state of California. As of the 2010 census, the population was 3,010,232 making it the third-most populous county in California, the sixth-most populous in the United States, and it more populous than twenty-one U.S. states. Its county seat is Santa Ana. Wikipedia