| Amboy High School | Amboy | Northwest | 2021 |
| Bloomington High School | Bloomington | Cenois | 2021 |
| Catalyst Maria High School | Chicago | Chicago | 2021 |
| Century High School | Ullin | Little Egypt | 2021 |
| Chicago Collegiate Charter High School | Chicago | Chicago | 2021 |
| Curie Metropolitan High School | Chicago | Chicago | 2021 |
| Edwards County High School | Albion | Eastern | 2021 |
| Eisenhower High School | Decatur | Cenois | 2021 |
| Eldorado High School | Eldorado | Little Egypt | 2021 |
| Elk Grove High School | Elk Grove Village | Northeast | 2021 |
| First Baptist Academy | O'Fallon | Kaskaskia | 2021 |
| Flora High School | Flora | Eastern | 2021 |
| Foreman High School | Chicago | Chicago | 2021 |
| Freeburg High School | Freeburg | Kaskaskia | 2021 |
| Glenbrook South High School | Glenview | Northeast | 2021 |
| Henry-Senachwine High School | Henry | Hopewell | 2021 |
| Iroquois West High School | Gilman | Prairie 8 | 2021 |
| Johnsburg High School | Johnsburg | North Central | 2021 |
| Joliet Central High School | Joliet | Prairie 8 | 2021 |
| Judah Christian High School | Champaign | Kickapoo | 2021 |
| Keith Country Day School | Rockford | North Central | 2021 |
| Kelly High School | Chicago | Chicago | 2021 |
| Leyden High School | Franklin Park | Northeast | 2021 |
| Mendota High School | Mendota | Prairie 8 | 2021 |
| Pawnee High School | Pawnee | Cenois | 2021 |
| Peoria High School | Peoria | Hopewell | 2021 |
| Peotone High School | Peotone | Prairie 8 | 2021 |
| Plainfield North High School | Plainfield | Prairie 8 | 2021 |
| Proviso East High School | Maywood | Northeast | 2021 |
| Putnam County High School | Granville | Hopewell | 2021 |
| Ramsey High School | Ramsey | Eastern | 2021 |
| Riverton High School | Riverton | Cenois | 2021 |
| Roycemore High School | Evanston | Northeast | 2021 |
| South Central High School | Farina | Eastern | 2021 |
| St. Anne Community High School | St. Anne | Prairie 8 | 2021 |
| St. Francis de Sales High School | Chicago | Chicago | 2021 |
| Unity High School | Tolono | Kickapoo | 2021 |
| Waltonville High School | Waltonville | Little Egypt | 2021 |
| Winchester High School | Winchester | Illinois Valley | 2021 |