Sun City is a former census-designated place in Riverside County, California, United States, and now a neighborhood of the city of Menifee, California. Along with the neighboring communities of Quail Valley and Menifee, it was incorporated as part of the City of Menifee on October 1, 2008. The population when Sun City was a CDP was 17,773 at the 2000 census. Sun City is located along Interstate 215 just south of the city of Perris.