| Raynor Country Day School | 5.2 |
Regular elementary or secondary | Pre-KG-6 | 97 | 3.4 | Nonsectarian |
| St Isidore School | 10.4 |
Regular elementary or secondary | Pre-KG-8 | 242 | 17.2 | Roman Catholic |
| Emanuel Lutheran School | 11.9 |
Regular elementary or secondary | Pre-KG-8 | 113 | 8.5 | Lutheran Church - Missouri Synod |
| Holy Angels Regional School | 12.2 |
Regular elementary or secondary | KG-8 | 385 | 16.8 | Roman Catholic |
| Step By Step Early Learning Center | 13.1 |
Montessori | Pre-KG-Trans. KG | 11 | 5.5 | Nonsectarian |
| Montessori School Of Selden | 13.5 |
Early childhood program/child care center | Pre-KG-KG | 7 | 7.0 | Nonsectarian |
| North Shore Christian School | 15.7 |
Regular elementary or secondary | Pre-KG-8 | 108 | 5.7 | Baptist |
| Prince Of Peace Regional School | 15.9 |
Regular elementary or secondary | Pre-KG-8 | 172 | 11.6 | Roman Catholic |
| Kids Place Early Childhood Day School | 15.9 |
Montessori | Pre-KG-KG | 11 | 11.0 | Nonsectarian |
| St Elizabeth | 16.0 |
Regular elementary or secondary | Pre-KG-8 | 212 | 19.6 | Roman Catholic |
| Our Redeemer Lutheran School | 16.4 |
Regular elementary or secondary | Pre-KG-6 | 60 | 7.7 | Lutheran Church - Missouri Synod |
| West Sayville Christian School | 17.0 |
Regular elementary or secondary | KG-8 | 74 | 6.8 | Christian (no specific denomination) |
| Kiddie Academy E Setauket | 17.2 |
Early childhood program/child care center | Pre-KG-KG | 14 | 14.0 | Nonsectarian |
| Maimonides Day School | 17.2 |
Regular elementary or secondary | Pre-KG-6 | 11 | 3.2 | Jewish |
| St Joseph School | 17.3 |
Regular elementary or secondary | Pre-KG-8 | 186 | 12.5 | Roman Catholic |
| Our Lady Of Wisdom Regional School | 17.5 |
Regular elementary or secondary | KG-8 | 219 | 15.8 | Roman Catholic |
| Southampton Montessori School | 19.6 |
Montessori | Pre-KG-KG | 12 | 7.5 | Nonsectarian |
| Ca Montessori Children's Center | 20.2 |
Early childhood program/child care center | Pre-KG-KG | 16 | 4.6 | Nonsectarian |
| Tutor Time | 20.4 |
Early childhood program/child care center | Pre-KG-KG | 8 | 8.0 | Nonsectarian |
| North Shore Montessori | 20.5 |
Montessori | Pre-KG-KG | 19 | 4.8 | Nonsectarian |
| Sts Philip And James School | 20.6 |
Regular elementary or secondary | Pre-KG-8 | 284 | 15.3 | Roman Catholic |
| Harbor Country Day School | 20.6 |
Regular elementary or secondary | Pre-KG-8 | 120 | 8.6 | Nonsectarian |
| St Patrick Elementary School | 20.8 |
Regular elementary or secondary | Pre-KG-8 | 441 | 17.9 | Roman Catholic |
| Our Lady Of Mercy Regional School | 21.5 |
Regular elementary or secondary | Pre-KG-6 | 153 | 20.4 | Roman Catholic |
| Our Lady Of Providence Regional School | 21.7 |
Regular elementary or secondary | Pre-KG-8 | 280 | 17.5 | Roman Catholic |
| Our/lady Of The Hampstons | 21.7 |
Regular elementary or secondary | Pre-KG-8 | 285 | 13.2 | Roman Catholic |
| St Mary School | 21.9 |
Regular elementary or secondary | Pre-KG-8 | 426 | 12.5 | Roman Catholic |
| Ivy League School | 21.9 |
Regular elementary or secondary | Pre-KG-5 | 76 | 8.8 | Nonsectarian |
| Ebenezer Christian Academy | 24.6 |
Regular elementary or secondary | Pre-KG-4 | 53 | 13.2 | Assembly of God |
| Mdq Academy | 24.8 |
Regular elementary or secondary | Pre-KG-3 | 51 | 7.3 | Islamic |
