Menlo was established in 1915 and is located at 50 Valparaiso Avenue, across the street from Menlo Park. During its early years, the school included a junior college that became a college bearing the name Menlo College. In 1994, Menlo School and the College formally separated, but they continued to share their dining hall until 2017. Menlo School is accredited by the Western Association of Schools and Colleges and is a member of the National and California Associations of Independent Schools. The middle school consists of approximately 230 students; the high school is significantly larger, with roughly 570 students.