A day/boarding school for boys, Belmont Hill School is significant for an evolving campus plan and Hamilton Chapel, a model historic preservation effort. A former private estate, Belmont Hill grew into an academic village and matured as a mostly interconnected complex with internal quadrangles.

Belmont Hill's rocky twenty-nine-acre hilltop campus slopes down to the marshy banks of Winn Creek. Its Georgian Revival brick residence (1919), built on speculation by the Belmont Hill Trust, was vacant until 1923, when the trust made it a school and hired Reginald Heber Howe as headmaster. With architects Little and Russell, Howe planned additions to the core, now named Shaler House. Detached buildings followed in a domestic-scale village: The Cottage (1923), Eliot (1926), Atkins (1928), and two dormitories: Underwood (1931) and Speare (1938, John Radford Abbot). Only the Field House (1929, 1950 expansion, Henry L. Kennedy) exceeded village scale. As enrollments increased after World War II, Belmont Hill built larger buildings—Morse (1946, E. M. Bridge) and Howe Science (1957, Charles Horton), now the Middle School—and began to form quadrangles.

The Greek Revival Hamilton Chapel anchors the main quadrangle. Built in the town of West Thompson, Connecticut, in 1840, it was scheduled for demolition when the town was razed for a flood control reservoir. Local preservationist Roger Webb acquired the church, disassembled it into ten thousand numbered pieces, and shipped it in thirty trucks to Belmont.

Larger recent campus additions include the Meyer Science Center (1974, Drummey Rosane Anderson; 1997 remodeled, Jeffrey Millman Associates) and the remodeling of Shaler House into the Lynch Computer Center and adding Byrnes Library (both 1987, CBT/Childs Bertman Tseckares). Belmont Hill followed the trend of other schools in the 1990s, adding the large Jordan Athletic Center in 1999–2000.