Tustin, CA has a population of 79,396 and is the 436th largest city in the United States. The population density is 7,140 per sq mi which is 2973% higher than the California average and 7781% higher than the national average. The median age in Tustin is 34 which is approximately 5% lower than the California average of 36. In Tustin, 51% of the population over 15 years of age are married, 45% speak English and 35% speak Spanish. 50% of Tustin residents were born in California, 13% were born out of state, 1% were born outside of the United States and 36% were foreign born.