Tustin Unified School District was created from the 1972 voter-approved unification of the Tustin Elementary School District and the Tustin Union High School District. It is located in Tustin, a city in Orange County, California. Its district territory comprises Tustin, the unincorporated community of North Tustin, and parts of the cities of Irvine and Santa Ana. It has 18 elementary schools, five middle schools, four high schools, one K-8 school, and one adult school.

Tustin is a city located in Orange County, California, United States, within the Los Angeles metropolitan area. In 2020, Tustin had a population of 80,276. The city does not include the unincorporated community of North Tustin.