Del Mar High School (DMHS) is a four-year, public secondary school established in 1959 in San Jose, California. It is part of the Campbell Union High School District, (CUHSD), the other schools in which are Branham, Leigh, Prospect, and Westmont. Most of Del Mar's students come from the Campbell Union School District's Monroe Middle School. The school serves both San Jose and Campbell, in addition to some unincorporated pockets of Santa Clara County. In 2016, Del Mar became an International Baccalaureate school. The first class who started the diploma, was the class of 2018.

The school mascot of Del Mar is "The Don", and the colors are black, gold, and, officially, white. As of 2024 the school principal is Diana Nguyen. In recent years, the school's academic scores have risen significantly, most notably by reaching an API (Academic Performance Index) score of 720 in 2011, a jump of 122 points since 2004. In 2007, it was officially deemed a "California Distinguished School".