San Dimas, CA has a population of 34,109 and is the 1,243rd largest city in the United States. The population density is 2,268 per sq mi which is 876% higher than the California average and 2404% higher than the national average. The median age in San Dimas is 42 which is approximately 17% higher than the California average of 36. In San Dimas, 60% of the population over 15 years of age are married, 72% speak English and 14% speak Spanish. 64% of San Dimas residents were born in California, 16% were born out of state, 1% were born outside of the United States and 19% were foreign born.