#1 Largest Private Schools in Allegheny County, PA
Shady Side Academy
Independent school · Grades Pre-K–12
1,118 students
Pittsburgh, PA
B+Overall grade1,118 students21 students per teacher
2026 lists
Largest Private Schools in Allegheny County, PA
The private schools in Allegheny County, PA with the most students. Top 50 of 95 schools.
#2 Largest Private Schools in Allegheny County, PA
Shady Side Academy
Independent school · Grades Pre-K–12
1,118 students
Pittsburgh, PA
A-Overall grade1,118 students8 students per teacher
#3 Largest Private Schools in Allegheny County, PA
Central Catholic High School
Diocesan school · Grades 9–12
712 students
Pittsburgh, PA
A+Overall gradeAll boys712 students12 students per teacher
#4 Largest Private Schools in Allegheny County, PA
Winchester Thurston School
Independent school · Grades Pre-K–12
645 students
Allison Park, PA
A+Overall grade645 students9 students per teacher
#5 Largest Private Schools in Allegheny County, PA
Eden Christian Academy
Christian school (nondenominational) · Grades K–12
643 students
Pittsburgh, PA
BOverall grade643 students11 students per teacher
#6 Largest Private Schools in Allegheny County, PA
St. Louise De Marillac School
Diocesan school · Grades Pre-K–8
511 students
Pittsburgh, PA
B-Overall grade511 students20 students per teacher
#7 Largest Private Schools in Allegheny County, PA
Trinity Christian School
Christian school (nondenominational) · Grades K–12
449 students
Wilkinsburg, PA
BOverall grade449 students14 students per teacher
#8 Largest Private Schools in Allegheny County, PA
Sewickley Academy
Independent school · Grades Pre-K–12
445 students
Sewickley, PA
A+Overall grade445 students7 students per teacher
#9 Largest Private Schools in Allegheny County, PA
Seton Lasalle Catholic High School
Diocesan school · Grades 9–12
433 students
Pittsburgh, PA
A-Overall grade433 students12 students per teacher
#10 Largest Private Schools in Allegheny County, PA
Falk Laboratory School
Independent school · Grades K–8
432 students
Pittsburgh, PA
A+Overall grade432 students7 students per teacher
#11 Largest Private Schools in Allegheny County, PA
Sacred Heart Elementary School
Parish school · Grades Pre-K–8
409 students
Pittsburgh, PA
BOverall grade409 students17 students per teacher
#12 Largest Private Schools in Allegheny County, PA
Grace Non-Traditional Christian Academy
Alternative school · Grades 9–12
407 students
Pittsburgh, PA
B-Overall grade407 students
#13 Largest Private Schools in Allegheny County, PA
Oakland Catholic High School
Diocesan school · Grades 9–12
400 students
Pittsburgh, PA
A+Overall gradeAll girls400 students10 students per teacher
#14 Largest Private Schools in Allegheny County, PA
Ellis School
Independent school · Grades Pre-K–12
367 students
Pittsburgh, PA
A+Overall gradeAll girls367 students6 students per teacher
#15 Largest Private Schools in Allegheny County, PA
Hillel Academy Pittsburgh
Jewish day school · Grades Pre-K–12
356 students
Pittsburgh, PA
B-Overall grade356 students7 students per teacher
#16 Largest Private Schools in Allegheny County, PA
Our Lady of the Sacred Heart High School
Independent Catholic school · Grades 9–12
335 students
Coraopolis, PA
A-Overall grade335 students11 students per teacher
#17 Largest Private Schools in Allegheny County, PA
Blessed Francis Seelos Academy
Diocesan school · Grades Pre-K–8
334 students
Wexford, PA
BOverall grade334 students15 students per teacher
#18 Largest Private Schools in Allegheny County, PA
Mother of Mercy Academy
Diocesan school · Grades Pre-K–8
298 students
Pittsburgh, PA
BOverall grade298 students14 students per teacher
#19 Largest Private Schools in Allegheny County, PA
Harvest Baptist Academy
Baptist school · Grades K–12
298 students
Natrona Heights, PA
BOverall grade298 students11 students per teacher
#20 Largest Private Schools in Allegheny County, PA
Mother of Mercy Academy
Diocesan school · Grades Pre-K–8
297 students
Pittsburgh, PA
B+Overall grade297 students13 students per teacher
#21 Largest Private Schools in Allegheny County, PA
Hillel Academy-Boys H.S.
Jewish day school · Grades K–12
293 students
Pittsburgh, PA
BOverall grade293 students6 students per teacher
#22 Largest Private Schools in Allegheny County, PA
Archangel Gabriel School
Diocesan school · Grades Pre-K–8
286 students
Mc Kees Rocks, PA
B-Overall grade286 students16 students per teacher
#23 Largest Private Schools in Allegheny County, PA
Ave Maria Academy - Bethel Campus
Diocesan school · Grades Pre-K–8
280 students
Pittsburgh, PA
B-Overall grade280 students21 students per teacher
#24 Largest Private Schools in Allegheny County, PA
St. Edmund's Academy
Independent school · Grades Pre-K–8
270 students
Pittsburgh, PA
A+Overall grade270 students7 students per teacher
From official public records, updated October 2026.