#1 Best Private High Schools in Union County, NJ
Mother Seton Regional High School
Diocesan school · Grades 9–12
The only Catholic school in Clark
Clark, NJ
A+Overall gradeAll girls181 students8 students per teacher
2026 lists
Best Private High Schools in Union County, NJ
Private high schools in Union County, NJ with the highest overall grades. Top 8 of 8 schools.
#2 Best Private High Schools in Union County, NJ
Union Catholic Regional High School
Diocesan school · Grades 9–12
100% of graduates go to four-year colleges
Scotch Plains, NJ
A+Overall grade530 students10 students per teacher
#3 Best Private High Schools in Union County, NJ
Oak Knoll School of the Holy Child
Independent Catholic school · Grades Pre-K–12
Smaller classes than 85% of Catholic schools nationwide
Summit, NJ
A+Overall grade498 students6 students per teacher
#4 Best Private High Schools in Union County, NJ
Flexschool
Independent school · Grades K–12
The only independent school in Berkeley Heights
Berkeley Heights, NJ
A+Overall grade98 students3 students per teacher
#5 Best Private High Schools in Union County, NJ
Kent Place School
Independent school · Grades Pre-K–12
The only independent school in Summit
Summit, NJ
A+Overall gradeAll girls636 students7 students per teacher
#6 Best Private High Schools in Union County, NJ
Bruriah High School for Girls
Jewish day school · Grades 6–12
The only all-girls school in Elizabeth
Elizabeth, NJ
A+Overall gradeAll girls213 students4 students per teacher
#7 Best Private High Schools in Union County, NJ
Oratory Prep School
Independent Catholic school · Grades 7–12
The only all-boys school in Summit
Summit, NJ
A+Overall gradeAll boys363 students9 students per teacher
#8 Best Private High Schools in Union County, NJ
Rav Teitz Mesivta Academy (Jec High School)
Jewish day school · Grades 6–12
The only all-boys school in Elizabeth
Elizabeth, NJ
B-Overall gradeAll boys210 students14 students per teacher
Grades compare each school's official facts, such as class size, how long it has served families and where graduates go, with similar schools. They're a starting point: visit, ask questions and trust what you see.