In 1901 two sisters, Charlotte Drinkwater and Mary Drinkwater Warren, established a self-sustaining school for poor and homeless boys on their farm in Greenwich, Massachusetts. Characterized by practicality and compassion, the school reflected the sisters’ selfless desire to provide a home and basic education for young boys in need.
In 1927, with the flooding of the Swift River Valley to create the Quabbin Reservoir imminent, Hillside School moved to its present location in Marlborough. Throughout the tenures of five headmasters, who faced chronic financial difficulties particularly during the Great Depression and two world wars, Hillside continued to provide a haven for boys who had nowhere else to go. Until the 1980's, the farm was central to the school’s existence. The boys grew crops and raised cattle, pigs and chickens, providing food for the entire community.
From its earliest years, Hillside was sustained in countless way by the Daughters of the American Revolution.
In 2005, Phase I of the campus buildout and curriculum enhancement program was complete in conjunction with all other initiatives of the April 2005 Strategic Plan and Dare to Lead! campaign. Phase II - The Campaign for Hillside - began with the construction of The Maher House dorm, three new tennis courts, and the expansion of the Dining Room and Wick Tutorial Center. In March 2008, Hillside opened a multimillion dollar Academic & Health Center. The Chase Chapel and two new athletic fields - including the Doran Baseball Diamond - were completed in 2009. In January 2010, Hillside published a three year plan that would continue to expand the campus and enhance the programs of the school.
Today, Hillside has solidified its reputation as a premier junior boarding school providing structured, supportive, and challenging academic opportunities to a diverse population of young adolescent boys in grades 5 to 9, both traditional learners and those with learning differences, in preparation for secondary school. The Campaign for Hillside will finish in the next few years with the building of a new athletic center, the development of new center for the arts and the doubling of the school's endowment.