Menlo School

Menlo School was founded in 1915 as the William Warren School, an all-male military school with an inaugural enrollment of 13 boys. Warren, the founder and headmaster, sold the school in 1924 to a group of parents, who dropped the military focus and formed a new corporation under the name Menlo School for Boys.

In 1927, Menlo became a non-profit governed by a newly created board of trustees. A two-year junior college, Menlo College, was created that year as an expansion of the school. During the college's early years, Menlo offered a hybrid prep school and junior college education. Students would attend the school for the latter two years of high school, then the college for two years, and then transferred directly into four-year universities as upper-division students.

In the fall of 1979, Menlo School began transitioning from a boys-only school with a small boarding program to a coeducational day school. In the 1993–1994 academic year, Menlo further moved to increase the upper school's enrollment, added grade 6 to the middle school, and further expanded its female enrollment.

The college and school were split on June 30, 1994, with further, more specific separations following. Menlo School and Menlo College became formally independent entities with separate boards, administrations, and faculties. In 2008, they further agreed to the formal legal subdivision of their hitherto shared land into two separate parcels. The only area of the campus that continues to be jointly owned and managed is the Menlo Athletic Quad, consisting of the athletic fields and track.

Following a fundraising effort that began in the late 1990s, both the middle and upper school campuses have been mostly rebuilt. The projects were completed in 1999 and 2004, respectively.