Santa Rosa, CA has a population of 173,165 and is the 146th largest city in the United States. The population density is 4,193 per sq mi which is 1704% higher than the California average and 4528% higher than the national average. The median age in Santa Rosa is 38 which is approximately 6% higher than the California average of 36. In Santa Rosa, 51% of the population over 15 years of age are married, 69% speak English and 24% speak Spanish. 61% of Santa Rosa residents were born in California, 18% were born out of state, 1% were born outside of the United States and 19% were foreign born.