The school's history traces back to the Clinton Academy, which opened its doors in 1785. The school was named for former New York governor
George Clinton. Land on Newtown Lane in the
village of East Hampton was purchased from Isaac Osborn in 1894, allowing the school to move into a "larger and better-equipped" wooden building, according to a 1960 school handbook. The first graduating class in 1895 had six students. In 1922, the grade school (one of two school buildings) was torn down to make way for a new facility. The high school building was moved to the corner of
Main Street and Fithian Lane, replacing the original Clinton Academy as a municipal building,. A new brick school building opened in 1924 to serve primary and secondary education. In 1961, elementary students moved to a new building, later named for elementary principal John M. Marshall. A$49-million expansion was completed in 2010. The project included of new space and renovated of existing space, including a new cafeteria, library, gymnasium, and district and school offices, and multi-purpose classrooms, as well as an energy-efficient "cool roof." ==Athletics==