| Twin City Christian School | 2.8 |
Regular elementary or secondary | Pre-KG-12 | 191 | 12.2 | Baptist |
| Mary Mcleod Bethune Institute | 8.4 |
Special program emphasis | 3-12 | 45 | 8.0 | Nonsectarian |
| Sterling Nursery School | 9.4 |
Special education | Pre-KG-Pre-KG | 3 | 0.8 | Nonsectarian |
| Seven Hills Academy | 10.0 |
Special education | 4-12 | 60 | 14.6 | Nonsectarian |
| Seven Hills At Groton | 11.7 |
Special education | 1-12 | 25 | 8.3 | Nonsectarian |
| South Lancaster Academy And Browning Elementary | 11.7 |
Regular elementary or secondary | Pre-KG-12 | 237 | 15.0 | Seventh-Day Adventist |
| Pepperell Christian Academy | 12.3 |
Regular elementary or secondary | Pre-KG-12 | 29 | 5.5 | Baptist |
| Rfk Lancaster School | 12.9 |
Special education | 4-12 | 36 | 1.1 | Nonsectarian |
| Cottage Hill Academy | 13.0 |
Special education | 6-12 | 32 | 4.0 | Nonsectarian |
| Devereux School | 16.4 |
Special education | 1-12 | 114 | 6.7 | Nonsectarian |
| Nashoba Learning Group | 17.4 |
Special education | Pre-KG-11 | 40 | 0.8 | Nonsectarian |
| Hillside School | 19.6 |
Regular elementary or secondary | 5-9 | 139 | 6.0 | Nonsectarian |
| Stetson School | 19.8 |
Special education | 4-12 | 111 | 6.9 | Nonsectarian |
| Bancroft School | 19.9 |
Regular elementary or secondary | KG-12 | 562 | 7.7 | Nonsectarian |
| Mercy Centre | 20.0 |
Special education | Ungraded-Ungraded | 24 | 6.0 | Roman Catholic |
| Lighthouse School | 21.6 |
Special education | Pre-KG-12 | 220 | 6.7 | Nonsectarian |
| Yeshiva Achei Tmimim Academy | 22.2 |
Regular elementary or secondary | Pre-KG-12 | 86 | 4.2 | Jewish |
| Kathleen Burns Preparatory School | 22.5 |
Special education | 5-12 | 36 | 5.1 | Nonsectarian |
| G Stanley Hall School | 22.8 |
Special education | 3-12 | 43 | 6.1 | Nonsectarian |
| Archway Inc | 23.3 |
Special education | 5-12 | 13 | 4.5 | Nonsectarian |
| Worcester Academy | 23.5 |
Regular elementary or secondary | 6-12 | 631 | 8.9 | Nonsectarian |
| Willow Hill School | 23.7 |
Special education | 6-12 | 60 | 3.4 | Nonsectarian |
| Riverside School | 23.9 |
Special education | 2-12 | 34 | 4.9 | Nonsectarian |
| Fay School | 24.2 |
Regular elementary or secondary | 1-9 | 379 | 6.6 | Nonsectarian |
| Merrimack Schools | 24.2 |
Alternative/other | 5-12 | 55 | 2.5 | Nonsectarian |
| The Fenn School | 24.6 |
Regular elementary or secondary | 4-9 | 304 | 8.2 | Nonsectarian |
| Valley View School | 25.0 |
Alternative/other | Ungraded-Ungraded | 56 | 4.7 | Nonsectarian |
