At A Glance

  • Year Established: 1957
  • Location: Boston, MA
  • Type of School: Private MS. CO-ED
  • Website:
  • Grades: 9-12
  • Total Enrollment: 145
  • Teacher to Student Ratio: 1:5
  • Faculty Holds Advanced Degree: 1:5
  • Average Class Size: 12
  • Accreditation: NEASC
  • Average SAT Score: 2206


The mission of Commonwealth School is to educate young people from diverse backgrounds to become knowledgeable, thoughtful, and creative adults, capable of careful analysis, fruitful cooperation, responsible leadership, and deep commitment.

Commonwealth aims tobe a school:

  • with the highest standards of academic excellence
  • where students learn to think for themselves, to exercise responsibility and initiative in their actions
  • with a community of talented teachers and promising students from diverse backgrounds
  • that takes maximum advantage of its rich urban setting
  • where arts are a vital element of daily life
  • that equips students to use effectively a wide range of tools for inquiry and research
  • that promotes physical and emotional health and fitness
  • that provides the friendly atmosphere of a small, supportive community
  • that helps students establish the foundation for rewarding and productive lives 

In keeping with our mission, our gifted and accomplished teachers set the highest standards and work hard to help their students meet them. In the liveliness and warmth of a small yet richly varied community, classmates’ talents and curiosity often generate much of the excitement.

As they move through grades 9-12, our students develop a large shared frame of reference: cell biology, visual and performing arts, Greek and Roman history, Hamlet, and their own collective creativity and sense of humor. They also learn about the city around them both formally and informally, through courses, independent projects, and community service.


English, Mathematics, Science, History, Languages, Computer Science, Humanities and Social Sciences, Visual and Performing Arts


Soccer, Basketball, Fencing, Cross-Country, Ultimate Frisbee, Running, Fitness, Ballroom Dance, Sailing, Squash, Dance, Yoga

Activities and Clubs

Diversity Committee, Model Congress, Model United Nations, Environmental Club, Commonwealth Cares, Math Team, Robotics Club, Debate Team, Science Team, Amnesty, Newspaper, Prom, Lit Mag, Chess Club, Yearbook (Clubs may be subject to change based on annual participation) 

Where Our Graduates Go

Harvard University, University of Chicago, Tufts University, Brown University, Harvard University, Brandeis University, Columbia University, Cornell University, Massachusetts Institute of Technology, Princeton University, Yale University, New York University, Northwestern University, Duke University, Stanford University, Boston University, Washington University in St. Louis, Carleton College, and McGill University, and more.