| Archbishop Ryan High School (USA) | - | Varsity | Small | 0 | | |
| Archbishop Shaw High School | - | Varsity | Medium | 0 | | |
| Archbishop Spalding High School | - | Varsity | - | 0 | | |
| Archbishop Wood High School | - | Junior | Large | 0 | | |
| Archbishop Wood High School | - | Varsity | Small | 0 | | |
| Archbishop Wood High School | - | Varsity | Small | 0 | | |
| Ardsley High School | - | Varsity | Small | 0 | | |
| Ardsley High School | - | Varsity | Small | 0 | | |
| Arizona College Preparatory | - | - | - | 0 | | |
| Arizona College Preparatory | - | Varsity | Small | 0 | | |
| Arthur L. Johnson High School | - | Varsity | Small | 0 | | |
| Arvada West High School | - | Junior | Small | 0 | | |
| Arvada West High School | - | Junior | - | 0 | | |
| Ascension Catholic High School | - | Varsity | Small | 0 | | |
| Ascension Episcopal School | - | Varsity | Medium | 0 | | |
| Assabet Valley Vocational High School | - | Varsity | Small | 0 | | |
| Assabet Valley Vocational High School | - | Varsity | Small | 0 | | |
| Assumption High School | - | Varsity | Small | 0 | | |
| Athens Drive High School | - | Varsity | Small | 0 | | |
| Athens Drive High School | - | Varsity | Small | 0 | | |
| Athens Drive High School | - | Varsity | Small | 0 | | |
| Atherton High School | - | Varsity | - | 0 | | |
| Atherton High School | - | Varsity | Small | 0 | | |
| Atlantic Coast High School | - | Varsity | Medium | 0 | | |
| Auburn High School | - | Varsity | Small | 0 | | |