#1 Largest Private Schools in Boston, MA
British International School of Boston
Independent school · Grades Pre-K–12
481 students
Boston, MA
B+Overall grade481 students9 students per teacher
2026 lists
Largest Private Schools in Boston, MA
The private schools in Boston, MA with the most students. Top 16 of 16 schools.
#2 Largest Private Schools in Boston, MA
The Winsor School
Independent school · Grades 5–12
475 students
Boston, MA
A+Overall gradeAll girls475 students6 students per teacher
#3 Largest Private Schools in Boston, MA
Cathedral High School
Independent Catholic school · Grades 7–12
326 students
Boston, MA
A+Overall grade326 students9 students per teacher
#4 Largest Private Schools in Boston, MA
German International School Boston
Independent school · Grades Pre-K–12
256 students
Boston, MA
A+Overall grade256 students4 students per teacher
#5 Largest Private Schools in Boston, MA
The Newman School
Independent school · Grades 7–12
251 students
Boston, MA
A+Overall grade251 students5 students per teacher
#6 Largest Private Schools in Boston, MA
The Newman School
Independent school · Grades 7–12
244 students
Boston, MA
A+Overall grade244 students5 students per teacher
#7 Largest Private Schools in Boston, MA
Boston Trinity Academy
Christian school (nondenominational) · Grades 6–12
238 students
Boston, MA
A+Overall grade238 students7 students per teacher
#8 Largest Private Schools in Boston, MA
Boston University Academy
Independent school · Grades 9–12
233 students
Boston, MA
A+Overall grade233 students7 students per teacher
#9 Largest Private Schools in Boston, MA
Kingsley Montessori School
Montessori school · Grades Pre-K–6
184 students
Boston, MA
AOverall grade184 students5 students per teacher
#10 Largest Private Schools in Boston, MA
Park Street School
Christian school (nondenominational) · Grades Pre-K–6
162 students
Boston, MA
A+Overall grade162 students8 students per teacher
#11 Largest Private Schools in Boston, MA
The Advent School
Independent school · Grades Pre-K–6
161 students
Boston, MA
AOverall grade161 students6 students per teacher
#12 Largest Private Schools in Boston, MA
Commonwealth School
Independent school · Grades 9–12
154 students
Boston, MA
A+Overall grade154 students4 students per teacher
#13 Largest Private Schools in Boston, MA
St. John School
Diocesan school · Grades Pre-K–8
121 students
Boston, MA
A+Overall grade121 students7 students per teacher
#14 Largest Private Schools in Boston, MA
Learning Project Elementary School
Independent school · Grades K–6
118 students
Boston, MA
A+Overall grade118 students4 students per teacher
#15 Largest Private Schools in Boston, MA
Beacon Academy
Independent school · Grade 8
21 students
Boston, MA
B+Overall grade21 students7 students per teacher
#16 Largest Private Schools in Boston, MA
Torit Montessori School
Montessori school · Grades Pre-K–5
20 students
Boston, MA
B+Overall grade20 students6 students per teacher
From official public records, updated October 2026.