#1 Largest Private Schools in Nassau County, NY
Kellenberg Memorial High School
Independent Catholic school · Grades 6–12
2,692 students
Uniondale, NY
BOverall grade2,692 students22 students per teacher
2026 lists
Largest Private Schools in Nassau County, NY
The private schools in Nassau County, NY with the most students. Top 50 of 77 schools.
#2 Largest Private Schools in Nassau County, NY
Hebrew Academy of Five Towns & Rockaway
Jewish day school · Grades Pre-K–12
1,119 students
Lawrence, NY
A+Overall grade1,119 students6 students per teacher
#3 Largest Private Schools in Nassau County, NY
North Shore Hebrew Academy
Jewish day school · Grades Pre-K–12
1,116 students
Great Neck, NY
A-Overall grade1,116 students6 students per teacher
#4 Largest Private Schools in Nassau County, NY
Sacred Heart Academy
Diocesan school · Grades 9–12
677 students
Hempstead, NY
A+Overall gradeAll girls677 students14 students per teacher
#5 Largest Private Schools in Nassau County, NY
Portledge School
Independent school · Grades Pre-K–12
518 students
Locust Valley, NY
AOverall grade518 students8 students per teacher
#6 Largest Private Schools in Nassau County, NY
Yeshiva Ketana of Long Island
Jewish day school · Grades Pre-K–8
464 students
Inwood, NY
B-Overall gradeAll boys464 students22 students per teacher
#7 Largest Private Schools in Nassau County, NY
Long Island Lutheran Middle & High School
Lutheran (Missouri Synod) school · Grades 6–12
452 students
Glen Head, NY
A-Overall grade452 students12 students per teacher
#8 Largest Private Schools in Nassau County, NY
Hanc - Middle & High School
Jewish day school · Grades 7–12
422 students
Uniondale, NY
BOverall grade422 students8 students per teacher
#9 Largest Private Schools in Nassau County, NY
Davis Renov Stahler Yeshiva High School -Boys
Jewish day school · Grades 9–12
387 students
Woodmere, NY
BOverall gradeAll boys387 students7 students per teacher
#10 Largest Private Schools in Nassau County, NY
St. William the Abbot School
Parish school · Grades Pre-K–8
372 students
Seaford, NY
BOverall grade372 students13 students per teacher
#11 Largest Private Schools in Nassau County, NY
The Greenvale School
Independent school · Grades Pre-K–8
355 students
Old Brookville, NY
A+Overall grade355 students6 students per teacher
#12 Largest Private Schools in Nassau County, NY
Stella K. Abraham H.S. for Girls
Jewish day school · Grades 9–12
354 students
Hewlett, NY
B-Overall gradeAll girls354 students10 students per teacher
#13 Largest Private Schools in Nassau County, NY
The Brandeis School
Early childhood program · Kindergarten only
336 students
Lawrence, NY
B-Overall grade336 students18 students per teacher
#14 Largest Private Schools in Nassau County, NY
St. Mary's High School
Parish school · Grades 9–12
329 students
Manhasset, NY
A+Overall grade329 students13 students per teacher
#15 Largest Private Schools in Nassau County, NY
St. Marys High School
Parish school · Grades 9–12
329 students
Manhasset, NY
B+Overall grade329 students13 students per teacher
#16 Largest Private Schools in Nassau County, NY
St. Anne's School
Parish school · Grades Pre-K–8
323 students
Garden City, NY
A-Overall grade323 students14 students per teacher
#17 Largest Private Schools in Nassau County, NY
The Hagedorn Little Village School
Special education school · Ungraded
307 students
Seaford, NY
B-Overall grade307 students
#18 Largest Private Schools in Nassau County, NY
St. Martin De Porres Marianist School
Independent Catholic school · Grades Pre-K–8
298 students
Uniondale, NY
AOverall grade298 students12 students per teacher
#19 Largest Private Schools in Nassau County, NY
St. Dominic High School
Independent Catholic school · Grades 9–12
280 students
Oyster Bay, NY
A-Overall grade280 students11 students per teacher
#20 Largest Private Schools in Nassau County, NY
Our Lady of Victory School
Parish school · Grades Pre-K–8
279 students
Floral Park, NY
A+Overall grade279 students13 students per teacher
#21 Largest Private Schools in Nassau County, NY
Crescent School
Independent school · Grades K–12
270 students
Hempstead, NY
B+Overall grade270 students11 students per teacher
#22 Largest Private Schools in Nassau County, NY
Notre Dame School
Diocesan school · Grades Pre-K–8
267 students
New Hyde Park, NY
A+Overall grade267 students12 students per teacher
#23 Largest Private Schools in Nassau County, NY
Haftr Middle School
Jewish day school · Grades 6–8
262 students
Lawrence, NY
BOverall grade262 students7 students per teacher
#24 Largest Private Schools in Nassau County, NY
St. Rose of Lima Elementary School
Parish school · Grades Pre-K–8
250 students
Massapequa, NY
A+Overall grade250 students10 students per teacher
From official public records, updated October 2026.