Rialto, CA has a population of 102,418 and is the 300th largest city in the United States. The population density is 4,587 per sq mi which is 1874% higher than the California average and 4963% higher than the national average. The median age in Rialto is 29 which is approximately 19% lower than the California average of 36. In Rialto, 50% of the population over 15 years of age are married, 40% speak English and 57% speak Spanish. 62% of Rialto residents were born in California, 8% were born out of state, 1% were born outside of the United States and 28% were foreign born.