#1 Largest Private Schools in Middlesex County, NJ
St. Joseph High School
Independent Catholic school · Grades 9–12
571 students
Metuchen, NJ
AOverall gradeAll boys571 students13 students per teacher
2026 lists
Largest Private Schools in Middlesex County, NJ
The private schools in Middlesex County, NJ with the most students. Top 34 of 34 schools.
#2 Largest Private Schools in Middlesex County, NJ
Noor-Ul-Iman School
Islamic school · Grades Pre-K–12
527 students
Monmouth Junction, NJ
A+Overall grade527 students7 students per teacher
#3 Largest Private Schools in Middlesex County, NJ
Timothy Christian School
Christian school (nondenominational) · Grades K–12
452 students
Piscataway, NJ
A+Overall grade452 students10 students per teacher
#4 Largest Private Schools in Middlesex County, NJ
Wardlaw-Hartridge School
Independent school · Grades Pre-K–12
435 students
Edison, NJ
A+Overall grade435 students7 students per teacher
#5 Largest Private Schools in Middlesex County, NJ
St. Bartholomew School
Parish school · Grades Pre-K–8
401 students
East Brunswick, NJ
BOverall grade401 students19 students per teacher
#6 Largest Private Schools in Middlesex County, NJ
St. Francis Cathedral School
Diocesan school · Grades Pre-K–8
391 students
Metuchen, NJ
BOverall grade391 students16 students per teacher
#7 Largest Private Schools in Middlesex County, NJ
Wilberforce School
Christian school (nondenominational) · Grades Pre-K–12
344 students
Princeton, NJ
B+Overall grade344 students18 students per teacher
#8 Largest Private Schools in Middlesex County, NJ
St. Thomas the Apostle School
Diocesan school · Grades Pre-K–8
326 students
Old Bridge, NJ
BOverall grade326 students14 students per teacher
#9 Largest Private Schools in Middlesex County, NJ
Pillars Preparatory Academy
Islamic school · Grades Pre-K–12
289 students
South River, NJ
B+Overall grade289 students5 students per teacher
#10 Largest Private Schools in Middlesex County, NJ
Calvary Christian School
Christian school (nondenominational) · Grades Pre-K–12
288 students
Old Bridge, NJ
AOverall grade288 students9 students per teacher
#11 Largest Private Schools in Middlesex County, NJ
Darul Arqam School
Islamic school · Grades Pre-K–12
268 students
South River, NJ
A+Overall grade268 students8 students per teacher
#12 Largest Private Schools in Middlesex County, NJ
St. John Vianney School
Diocesan school · Grades Pre-K–8
247 students
Colonia, NJ
B+Overall grade247 students12 students per teacher
#13 Largest Private Schools in Middlesex County, NJ
Rabbi Pesach Raymon Yeshiva
Jewish day school · Grades Pre-K–8
231 students
Edison, NJ
A-Overall grade231 students6 students per teacher
#14 Largest Private Schools in Middlesex County, NJ
Yeshiva Shaarei Tzion Boys'
Jewish day school · Grades K–8
200 students
Piscataway, NJ
B-Overall gradeAll boys200 students13 students per teacher
#15 Largest Private Schools in Middlesex County, NJ
Assumption Catholic School
Religious school · Grades Pre-K–8
171 students
Perth Amboy, NJ
A+Overall grade171 students15 students per teacher
#16 Largest Private Schools in Middlesex County, NJ
St. Helena School
Parish school · Grades Pre-K–8
162 students
Edison, NJ
A+Overall grade162 students12 students per teacher
#17 Largest Private Schools in Middlesex County, NJ
Lakeview School
Special education school · Ungraded
143 students
Edison, NJ
A+Overall grade143 students6 students per teacher
#18 Largest Private Schools in Middlesex County, NJ
St. Stanislaus Kostka School
Parish school · Grades Pre-K–8
137 students
Sayreville, NJ
AOverall grade137 students11 students per teacher
#19 Largest Private Schools in Middlesex County, NJ
Metuchen Christian Academy
Assembly of God school · Grades K–8
135 students
Metuchen, NJ
BOverall grade135 students15 students per teacher
#20 Largest Private Schools in Middlesex County, NJ
St. James Elementary School
Diocesan school · Grades Pre-K–8
131 students
Woodbridge, NJ
AOverall grade131 students11 students per teacher
#21 Largest Private Schools in Middlesex County, NJ
Holy Savior Academy
Diocesan school · Grades Pre-K–8
121 students
South Plainfield, NJ
A+Overall grade121 students9 students per teacher
#22 Largest Private Schools in Middlesex County, NJ
Rabbi Jacob Joseph School
Jewish day school · Grades 9–12
118 students
Edison, NJ
B-Overall gradeAll boys118 students18 students per teacher
#23 Largest Private Schools in Middlesex County, NJ
French American School of Princeton
Independent school · Grades Pre-K–8
116 students
Princeton, NJ
A-Overall grade116 students8 students per teacher
#24 Largest Private Schools in Middlesex County, NJ
Immaculate Conception School
Diocesan school · Grades Pre-K–8
98 students
Spotswood, NJ
A+Overall grade98 students9 students per teacher
From official public records, updated October 2026.