| Developmental Disabilities Institute | 2.5 |
Special education | Ungraded-Ungraded | 228 | 6.3 | Nonsectarian |
| Nassau Suffolk Services For Autism | 2.8 |
Special education | Ungraded-Ungraded | 25 | 6.2 | Nonsectarian |
| Smithtown Christian School | 2.9 |
Regular elementary or secondary | Pre-KG-12 | 525 | 13.0 | Assembly of God |
| Academy Of St Joseph | 3.2 |
Regular elementary or secondary | KG-12 | 366 | 8.0 | Roman Catholic |
| Gersh Academy | 3.2 |
Special education | 3-12 | 56 | 3.6 | Nonsectarian |
| Ascent | 5.1 |
Special education | KG-11 | 23 | 2.1 | Nonsectarian |
| Upper Room Christian School | 5.3 |
Regular elementary or secondary | KG-12 | 310 | 9.0 | Christian (no specific denomination) |
| Nysarc Inc-suffolk Chapter | 5.8 |
Special education | Pre-KG-Pre-KG | 95 | 9.5 | Nonsectarian |
| Cleary School For The Deaf | 5.8 |
Special education | Pre-KG-12 | 45 | 2.9 | Nonsectarian |
| International Christian School | 8.2 |
Regular elementary or secondary | Pre-KG-12 | 67 | 7.4 | Baptist |
| Our Savior New American School | 9.1 |
Regular elementary or secondary | Pre-KG-12 | 235 | 5.2 | Lutheran Church - Missouri Synod |
| Long Island Baptist Academy | 10.4 |
Regular elementary or secondary | KG-12 | 34 | 7.1 | Baptist |
| Bethesda Sda Elementary | 11.7 |
Regular elementary or secondary | Pre-KG-10 | 123 | 15.8 | Seventh-Day Adventist |
| New Jerusalem Christian Academy | 12.1 |
Regular elementary or secondary | 2-12 | 45 | 15.0 | Pentecostal |
| The Center For Developmental Disabilities Inc | 12.3 |
Special education | Ungraded-Ungraded | 106 | 5.3 | Nonsectarian |
| Sappo School | 13.3 |
Special education | 5-12 | 35 | 5.8 | Nonsectarian |
| East Woods School | 13.3 |
Regular elementary or secondary | Pre-KG-9 | 239 | 5.3 | Nonsectarian |
| Variety Child Learning Center | 13.4 |
Special education | Pre-KG-Pre-KG | 59 | 1.1 | Nonsectarian |
| The Hagedorn Little Village School | 14.5 |
Special education | Pre-KG-Pre-KG | 60 | 7.7 | Nonsectarian |
| Long Island Lutheran Middle & High School | 15.9 |
Regular elementary or secondary | 6-12 | 614 | 13.1 | Lutheran Church - Missouri Synod |
| Mosaic School | 16.3 |
Special education | Ungraded-Ungraded | 3 | 0.9 | Nonsectarian |
| Ahrc Childrens Education Center | 17.4 |
Special education | Ungraded-Ungraded | 180 | 7.8 | Nonsectarian |
| Life Skills School | 17.6 |
Special education | Ungraded-Ungraded | 70 | 10.0 | Nonsectarian |
| Portledge School | 18.0 |
Regular elementary or secondary | Pre-KG-12 | 376 | 6.2 | Nonsectarian |
| Friends Academy | 18.5 |
Regular elementary or secondary | Pre-KG-12 | 717 | 7.6 | Friends |
| The Greenvale School | 18.8 |
Regular elementary or secondary | Pre-KG-9 | 426 | 6.3 | Nonsectarian |
| Kellenberg Memorial High School | 19.1 |
Regular elementary or secondary | 6-12 | 2511 | 20.8 | Roman Catholic |
| Grace Christian Academy | 19.2 |
Regular elementary or secondary | KG-11 | 80 | 8.5 | Baptist |
| Solomon Schechter Day School Of Nassau County | 19.7 |
Regular elementary or secondary | 6-12 | 328 | 5.8 | Jewish |
| School For Language & Communication Development | 20.5 |
Special education | Pre-KG-Pre-KG | 246 | 5.6 | Nonsectarian |
| Crescent School | 21.6 |
Regular elementary or secondary | KG-12 | 188 | 10.1 | Islamic |
| Leonard E Burket Christian School | 24.4 |
Regular elementary or secondary | Pre-KG-12 | 135 | 10.0 | Assembly of God |
