The school serves both San Jose and Campbell, in addition to some unincorporated pockets of Santa Clara County.

The school mascot of Del Mar is "The Don," and the colors are black, gold, and, officially, white.

In 2007, it was officially deemed a “California Distinguished School.” [4] The CUHSD began construction on the Del Mar campus in 1957; it was established in 1959.

Del Mar was the first complete four year high school in California to be constructed by the state's aid building fund, at a cost of $3 million.

In the 2005-2006 school year, several teams won the title of League Champions, including football, JV boys' soccer, badminton, and girls' swimming.

In 2009, the girls basketball team won a school-record 21 games and made it to the second round of CCS playoffs.

Del Mar repeated as the 2011 West Valley Division Football Champs with a league record of 7-3.

Del Mar also has a fairly successful Choir class, with plans to travel to Dublin in June 2018.

Past shows include 'Charlie Brown,' 'Twilight of the Golds,' 'Hamlet II,' ‘The Actor’s Nightmare,’ 'Thoroughly Modern Millie,' ‘Little Shop of Horrors,’ ‘Once Upon a Mattress,’ ‘Aida,’ ‘42nd Street,’ ‘A Funny Thing Happened on the way to the Forum,’ 'Don't Drink the Water,' 'Cinderella,' 'Girl Crazy,' ‘Grease,’ 'Guys & Dolls,' and others.

The first newspaper at Del Mar, published in 1962, three years after the school opened, was called the Excelsior.

An ASB card will get students into various events either for free (sports games), or for a reduced price (dances and performances).

Del Mar operates on a normal A through F system, with minor variation among teachers on which percentages correspond to which letter grades.

Del Mar also has "collaboration days" when seventh period doesn’t meet, and school ends at 1:15.

Also, Del Mar is on SchoolLoop, a program that allows teachers to post homework assignments, test dates, and notes online, in addition to providing the opportunity to communicate with their students by email.

[17] The administration/staff for Del Mar High School includes principal Diana Nguyen, assistant principals Loan Ly, Cedric Nguyen and Martha Bejar, counselors Evelyn Beas, Kristie Geist, Jenifer Martinez, and Amanda Perez, activities director Stacie Gardner, and athletics director Ryan Castaneda.

Laurance Hill was a principal of the old Campbell High School, and played an important role in the expansion of the CUHSD district.

Del Mar’s original wings on the north side of the quad, in addition to the band and drama rooms, the cafeteria/stage end of the building, the main office, teacher’s lounge, library, and student services center are all original buildings in Del Mar’s traditional brick.

It contains six classrooms, providing physics, chemistry, biology, and integrated science classes with high ceilings, projectors, and, in room 74, a balcony.

[20] The large and small gyms, locker rooms, and swimming pool, on the south side of the quad, are also original.

The big gym, home to basketball, volleyball, badminton, and several families of small birds which build nests in the old lights in the ceiling, received a new paint job in 2006 courtesy of the Don's Club.

Water polo cannot be played at Del Mar because of the pool's depth, or lack thereof.