2020-2021 ICNS Member Schools
| AAA Academy | Blue Island |
| All Saints Academy | Breese |
| Altamont Lutheran | Altamont |
| Arie Crown Hebrew Day School | Skokie |
| Bais Yaakov High School | Aurora |
| Brickton Montessori | Chicago |
| Calvary Academy | South Holland |
| Calvin Christian | South Holland |
| Chiaravalle Montessori | Evanston |
| Christ Lutheran High School | Buckley |
| Concordia Place | Chicago |
| Elgin Academy | Elgin |
| First Baptist Academy | O'Fallon |
| Good Shepherd | Collinsville |
| Hanna Sacks | Chicago |
| ICCD Academy | Des Plaines |
| Immanuel Lutheran | Palatine |
| Islamic Foundation | Villa Park |
| Joan Dachs Bais Yaakov | Chicago |
| Lake Forest County Day | Lake Forest |
| Lansing Christian | Lansing |
| Lycee Francais de Chicago | Chicago |
| MCC Academy | Morton Grove |
| Marmion Academy | Aurora |
| Montessori Foundations of Chicago | Chicago |
| Near North Montessori | Chicago |
| Ronald Knox Montessori | Wilmette |
| Science & Arts Academy | Des Plaines |
| Seton Montessori | Clarendon Hills |
| Solomon Schechter | Northbrook |
| Southwest Chicago Christian | Palos Heights |
| Springfield Christian | Springfield |
| St. Francis High School | Wheaton |
| St. John's Lutheran | Country Club Hills |
| St. Paul's Lutheran | Bourbonnais |
| The Ancona School | Chicago |
| Trinity Lutheran | Stewardson |
| Trinity Oaks Christian Academy | Cary |
| Universal | Bridgeview |
| Visitation | Elmhurst |