The legacy of Tustin's schools dates back to the 1860s - two decades before Orange County became independent of Los Angeles. Education was a priority of Tustin's namesake and community developer Columbus Tustin, a Petaluma carriage maker who purchased 839 acres in the 1860s and plotted streets and square blocks through a terrain of wild mustard and sycamore trees.
In 1872, he built a one-room schoolhouse and donated it to the community. Originally called Sycamore School District because of the abundant sycamore trees in the foothills, its first trustees were elected by 11 voters. Residents also approved a tax rate to provide $900 to build a larger schoolhouse and $300 for school supplies. The District's first teacher, Miss Annie Cozad, was paid $60 per month; its second teacher came five years later.
Tustin's plans for a large city were temporarily waylaid in 1877 when Southern Pacific Railroad built its southern terminus in Santa Ana instead of Tustin. Columbus Tustin died in 1883 just as the community's population began to grow with new homes, stores, places of worship, and an addition to the school.
The school district was renamed the Tustin School District with the creation of the County of Orange in 1889. After the turn of the century, Tustin grew as the upscale residential suburb of Santa Ana, the county seat of government. Tustin's homes and businesses reflected that upscale lifestyle and so did its schools.
Growth in the early 20th Century mirrored that of many Orange County communities with larger schools built to accommodate an expanding population. Tustin Union High School opened in 1922 and served five elementary school districts: Tustin, San Joaquin, Trabuco, El Toro, and Laguna. Residents voted for unification in 1972 and Tustin's elementary and high schools were unified as a single district - Tustin Unified School District.
Today the District serves over 19,500 students at 18 elementary schools, 5 middle schools, and 4 high schools (3 comprehensive high schools and 1 continuation school). Its administrative center is located at 300 South C Street in Tustin.