Moreno Valley is a city located in Riverside County, California. As of January 1, 2006, the population of Moreno Valley was 174,565. A relatively young city, its rapid growth in the 1980s and the 2000s propelled it to its status as second-largest city in Riverside County by population, and one of the Inland Empire's population centers. Neighboring Riverside, California is the county seat and largest city in the county; the two cities are closely tied, sharing March Air Reserve Base, among other things. Moreno Valley apartments for rent comparison page shows most up to date rent information on Moreno Valley apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.