Gunn High School opened in August 1964 with an initial enrollment of 600 students, comprising 300 sophomores and 300 juniors.

It was named after Henry Gunn, the superintendent of the Palo Alto Unified School District from 1950 to 1961.

[11] Gunn High School received national attention in 2009 after four of its students died of suicide over a span of seven months.

[16][17] In the past decade, attempts have been made to improve the psychological health of students attending the school.

[23] Hanna Rosin wrote in a 2015 The Atlantic article that due to the emphasis on academics and competition between students, Gunn became "an extreme distillation of what parents in the meritocratic elite expect from a school."

[19] Gunn offers a wide selection of mathematics courses ranging from Algebra to AP Calculus BC.

[28] Gunn is a host to Project Lead the Way (PLTW), an organization that promotes STEM (science, technology, engineering, and math) education.

[19] In 2012, the Robotics Team won the National FRC Championship Excellence in Design Award (3D Animation) sponsored by Autodesk.