The flagship of Sweetwater Union High School District, SUHI predominantly serves the National City community with an enrollment of 2,675 students.

Thanks to Proposition O, the Sweetwater Union High School District was able to fund a remodel of SUHI's aging campus.

This extensive upgrade, which incorporates some of the classic architecture in the new design, with a new three-story building housing the new counseling center, administration, library, theater, teacher offices, and 31 classrooms.

[6] Originally 80% of the campus was proposed to be redone, with a new quad and the replacement of the bungalows, but due to the “pay-to-play” scandal in Sweetwater Union High School District, only the “new building” was built after the contractors were fired.

To increase the number of SUHI students who continue to post-secondary education, the school has formed partnerships with University of California, San Diego, San Diego State University (through Compact for Success), and Southwestern College.