Vacaville, CA has a population of 95,607 and is the 327th largest city in the United States. The population density is 3,320 per sq mi which is 1329% higher than the California average and 3565% higher than the national average. The median age in Vacaville is 37 which is approximately 3% higher than the California average of 36. In Vacaville, 54% of the population over 15 years of age are married, 81% speak English and 12% speak Spanish. 61% of Vacaville residents were born in California, 25% were born out of state, 2% were born outside of the United States and 12% were foreign born.