| Caravel Academy | Bear | PreK-12 | 1,120 | 9.7 | Nonsectarian |
| Red Lion Christian Academy | Bear | K-12 | 695 | 9.5 | Christian (nondenominational) |
| Christ the Teacher Catholic School | Newark | PreK-8 | 524 | 22.8 | Roman Catholic |
| St. Mary Magdalen School | Wilmington | PreK-8 | 467 | 13 | Roman Catholic |
| St. John the Beloved School | Wilmington | PreK-8 | 459 | 17.9 | Roman Catholic |
| The Tatnall School | Wilmington | PreK-12 | 457 | 5.6 | Nonsectarian |
| Ursuline Academy, Lower | Wilmington | 3-8 | 456 | 7.8 | Roman Catholic |
| Immaculate Heart of Mary | Wilmington | PreK-8 | 406 | 16.4 | Roman Catholic |
| The Independence School | Newark | PreK-8 | 384 | 7.6 | Nonsectarian |
| St. Elizabeth School | Wilmington | PreK-12 | 364 | 12.2 | Roman Catholic |
| Holy Cross School | Dover | PreK-8 | 331 | 14.5 | Roman Catholic |
| Calvary Christian Academy | Dover | PreK-12 | 330 | 8.2 | Assembly of God |
| Greenwood Mennonite School | Greenwood | PreK-12 | 296 | 12.6 | Mennonite |
| St. Annes Episcopal School | Middletown | PreK-8 | 256 | 7.3 | Episcopal |
| St. Ann School | Wilmington | PreK-8 | 200 | 15.6 | Roman Catholic |
| Fairwinds Christian School | Bear | PreK-12 | 173 | 12 | Baptist |
| Epworth Christian School | Laurel | PreK-8 | 162 | 11.6 | Christian (nondenominational) |
| St. Anthony of Padua Grade School | Wilmington | PreK-8 | 161 | 9 | Roman Catholic |
| St. Edmond's Academy | Wilmington | PreK-8 | 158 | 8.6 | Roman Catholic, all-boys |
| The Pilot School | Wilmington | K-8 | 136 | 4.3 | Nonsectarian |
| Concord Christian Academy | Wilmington | PreK-12 | 136 | 8.6 | Baptist |
| Islamic Academy of Delaware | Newark | PreK-8 | 124 | 4.7 | Islamic |
| The Cross Christian Academy | Seaford | PreK-12 | 120 | 10 | Christian (nondenominational) |
| Milford Christian School | Milford | PreK-11 | 118 | 9.8 | Baptist |
| Central de Christian Academy | Dover | PreK-9 | 116 | 13 | Christian (nondenominational) |
| Harvest Christian Academy New Castle | New Castle | PreK-12 | 100 | 8.6 | Christian (nondenominational) |
| Harvest Christian Academy | New Castle | PreK-12 | 94 | 8.2 | Christian (nondenominational) |
| Centerville Layton School | Wilmington | K-12 | 88 | 3.2 | Nonsectarian |
| Urban Promise School | Wilmington | PreK-12 | 85 | 5.5 | Christian (nondenominational) |
| Aquinas Academy | Bear | K-12 | 75 | 8.9 | Roman Catholic |
| Newark Center for Creative Learning | Newark | K-8 | 73 | 6.5 | Nonsectarian |
| St. Peter Cathedral School | Wilmington | PreK-8 | 65 | 5.5 | Roman Catholic |
| Learning Express Academy | Newark | K-8 | 55 | 6.4 | Nonsectarian |
| Nativity Preparatory School of Wilmington | Wilmington | 5-8 | 53 | 7.6 | Roman Catholic, all-boys |
| The Hockessin Montessori School | Hockessin | PreK-8 | 47 | 2.8 | Nonsectarian |
| Green Hill | Dover | 1-8 | 46 | 15.3 | Amish |
| Dover First Christian School | Dover | PreK-8 | 45 | 11.5 | Seventh-Day Adventist |
| Serviam Girls Academy | Wilmington | 5-8 | 44 | 5.6 | Christian (nondenominational), all-girls |
| The College School | Newark | 2-8 | 43 | 4.4 | Nonsectarian |
| Shady Lane School | Hartly | 1-8 | 36 | 18 | Amish |