Co-ed independent day school in Boston's Back Bay for academically adventurous students in grades 9–12


Commonwealth students’ curiosity is limitless. They eagerly explore the contours and consequences of ideas, stretching their minds with everything from Modernist poetry to number theory. All the while, they ask why? And how? And what if? Driven by this intellectual passion—and the deep expertise of our college-caliber faculty—our classes nurture critical thinking, creativity, and a love of learning that lasts. 
If you share our enthusiasm for questions and discovery, if you’re keen to learn and to know, you should get to know us.



Uncommon Academics for Uncommonly Curious Students

In a world of ever-shortening attention spans, Commonwealth students and teachers dedicate themselves to deep, purposeful focus. Here you’ll learn to read closely and think with patience and tenacity. You’ll uncover the inner workings of molecules, of medieval history, and of the arts you pursue. You'll tap into Boston's vast scholarly research and experiential learning opportunities. And while you may not know what your academic passion is just yet, by diving into new topics, you will discover your interests. And at Commonwealth, you’ll be able to pursue them with full force.




student-to-faculty ratio


faculty with advanced degrees


average SAT composite score (Class of 2024)


AP scores 3 or above; 79% scores 4 or 5 (2022)


Exceptional Faculty

Our teachers are experts in their fields; eighty-five percent hold advanced degrees, and many have taught at colleges and universities. They were drawn to Commonwealth by the strength and dedication of our students, the small seminar-like classes (often taught at the college level), and the chance to help young scholars go farther than they ever imagined.
Yet, it’s their empathetic approach to teaching—a generosity with both their expertise and their time—that sets our faculty apart. Teachers know our students as individuals and spend hours talking about essay drafts, concepts that weren’t clear in class, or projects they’d like to pursue.


Commonwealth has the most amazing teachers. I'm so grateful to anyone who taught me during high school—I learned so much and was so well prepared for college. Having been in an environment with huge class sizes and professors who are more often focused on research than student learning, I can really say what a difference your individual care for students makes." Maya Venkatraman '17


Advising Program

Students meet with their advisors one-on-one, usually weekly, to discuss course work, talk through questions, and plan their courses of study. These close relationships are the foundation of a warm, close-knit community where individuality is cherished.

Learn More

College Counseling

Commonwealth’s college counseling program is a well-tuned process tailored to students’ individual needs. Close collaboration among student, parents and guardians, and advisor assures that our graduates wind up at colleges as stimulating and challenging as Commonwealth.

Learn More


Dive In Commonwealth

Dive In Commonwealth is a tuition-free academic enrichment program for promising, highly motivated middle school students from all over Boston and its surrounding communities. Students who demonstrate readiness for and interest in entering Commonwealth at the end of the program can join the school’s ninth-grade class and are eligible for need-based financial aid to ensure the affordability of a Commonwealth education.