Norco is a city in Riverside County, California, in the United States. As of the 2010 census, the city population was 27,063, up from 24,157 at the 2000 census. The city's name is an abbreviation of North Corona.. Norco is located at 33°55′38″N 117°33′41″W / 33.92722°N 117.56139°W / 33.92722; -117.56139 (33.927124, -117.561326).