Hamilton City, CA has a population of 2,135 and is the 10,638th largest city in the United States. The population density is 6,849 per sq mi which is 2847% higher than the California average and 7460% higher than the national average. The median age in Hamilton City is 33 which is approximately 10% lower than the California average of 36. In Hamilton City, 58% of the population over 15 years of age are married, 18% speak English and 79% speak Spanish. 59% of Hamilton City residents were born in California, 2% were born out of state, 2% were born outside of the United States and 36% were foreign born.