2021-2022 ICNS Member Schools
| Academy of St. Benedict the African | Chicago |
| Altamont Lutheran Interparish School | Altamont |
| Altus Academy | Chicago |
| American School | Lansing |
| Aqsa School | Bridgeview |
| Aurora Central Catholic High School | Aurora |
| Brother Rice High School | Chicago |
| Calvary Academy | South Holland |
| Calvary Academy | Springfield |
| Calvary Christian School | Chicago |
| Calvin Christian School | South Holland |
| Carriers of Light | Wheaton |
| Catherine Cook School | Chicago |
| Chicago Academy for the Arts | Chicago |
| Christ Lutheran School Association | Sterling |
| Christ the King Lutheran | Chicago |
| Christ the King School | Springfield |
| Cornerstone Christian School | Chicago Heights |
| Cornerstone Christian Academy | Bloomington |
| Elgin Academy | Elgin |
| Francis W. Parker | Chicago |
| Hanna Sacks High School | Chicago |
| Holy Family Parish School | Peoria |
| ICCD Academy | Des Plaines |
| Ida Crown Jewish Academy | Skokie |
| Illinois Lutheran Schools | Crete |
| Immanuel Christian Academy | Hillside |
| Immanuel Lutheran School | Elmhurst |
| Immanuel | Belvidere |
| Islamic Foundation School | Villa Park |
| JDBY-YTT | Chicago |
| Lutheran School Association of Decatur | Decatur |
| Lycee Francais de Chicago | Chicago |
| Marian Catholic High School | Chicago Heights |
| Montessori Foundations of Chicago | Chicago |
| Noonan Elementary Academy | Mokena |
| North Shore Country Day School | Winnetka |
| Our Savior's Lutheran | Springfield |
| Pilgrim Lutheran | Chicago |
| Pui Tak Christian School | Chicago |
| Ronald Knox Montessori School | Wilmette |
| Sacred Heart Schools | Chicago |
| Sacred Heart - Griffin | Springfield |
| Scuola Italiana Enrico Fermi | Chicago |
| South Side Christian Academy | Peoria |
| Spectrum School | Rockford |
| Springfield Christian School | Springfield |
| St. Dennis | Lockport |
| St. Edward Catholic | Elgin |
| St. James Lutheran | Quincy |
| St. John's Lutheran | Bloomington |
| St. Linus School | Oak Lawn |
| St. Patrick | Washington |
| St. Paul Lutheran | Chicago |
| St. Paul's Lutheran School | Bourbonnais |
| St. Peter | Arlington Heights |
| St. Peter Lutheran | Schaumburg |
| St. Theresa School | Palatine |
| The Avery Coonley School | Downers Grove |
| The Field School | Oak Park |
| The Frances Xavier Ward School | Chicago |
| Timothy Christian School | Elmhurst |
| Trinity Lutheran | Burr Ridge |
| Trinity Lutheran | Stewardson |
| Universal School | Bridgeview |
| Wheaton Christian Grammar School | Winfield |
| Willows Academy | Des Plaines |
| Zion Lutheran School | Marengo |
| Zion Lutheran School | Mt. Pulaski |
| Zion Lutheran School | Staunton |