| Association for the Advancement of Creative MusiciansChicago | Form 990-N | No figure |
| Dwight Athletic Boosters IncDwight | Form 990-N | No figure |
| American Chemical SocietyUrbana | Form 990-N | No figure |
| Iahss FoundationSchaumburg | Form 990-EZ | $43,754FY2025 |
| Princeton Tiger Athletic Booster Club IncPrinceton | Form 990-EZ | $43,676FY2025 |
| Henderson County Historical Society IncBiggsville | Form 990-N | No figure |
| Barker Farm OutreachPrinceton | Form 990-N | No figure |
| Migratory Waterfowl Hunters IncGodfrey | Form 990-EZ | $43,295FY2025 |
| Trout UnlimitedChicago | Form 990-EZ | $43,040FY2026 |
| Friends of the Highland Park Public Library IncHighland Park | Form 990-N | No figure |
| Eghm School District 7 FoundationEdwardsville | Form 990-EZ | $42,932FY2025 |
| Habitat for Humanity International IncGalesburg | Form 990-N | No figure |
| Golden Historical SocietyGolden | Form 990 | $42,773FY2025 |
| Parent Teacher Organization of North Barrington SchoolBarrington | Form 990-EZ | $42,393FY2026 |
| Hyde Park-Kenwood Community ConferenceChicago | Form 990-EZ | $42,295FY2024 |
| Norwood Park Historical SocietyChicago | Form 990 | $42,208FY2024 |
| Naperville Baseball Association IncNaperville | Form 990-N | No figure |
| National Taiwan University Medical College Alumni FoundationBurr Ridge | Form 990-N | No figure |
| New Town Alano Club IncChicago | Form 990-N | No figure |
| Illinois Congress of Parents TeachersWheaton | Form 990-EZ | $40,989FY2026 |
| Lasalle County Extension Service FoundationOttawa | Form 990-N | No figure |
| Little League Baseball IncFreeport | Form 990-N | No figure |
| Strawdog Theatre CompanyChicago | Form 990-N | No figure |
| J T Manning Elementary School Parent Teacher OrganizationWestmont | Form 990-N | No figure |
| Junior Service Club of St Clair CountyBelleville | Form 990-EZ | $39,664FY2025 |
| Illinois State Genealogical SocietySpringfield | Form 990-N | No figure |
| Illinois Solar Education Association IncElk Grove Village | Form 990-EZ | $38,965FY2025 |
| Dekalb County 4-H Foundation IncSycamore | Form 990-N | No figure |
| Auxiliary Council of Richland Memorial HospitalOlney | Form 990-EZ | $38,576FY2026 |
| American Society for Training and DevelopmentSpringfield | Form 990-N | No figure |
| Southwest Alano ClubChicago | Form 990-N | No figure |
| Illinois Congress of Parents TeachersElmhurst | Form 990-EZ | $38,015FY2025 |
| Glen Ellyn Rotary Club Foundation IncGlen Ellyn | Form 990-EZ | $37,942FY2025 |
| Little League Baseball IncMendota | Form 990-N | No figure |
| Izaak Walton League of AmericaForest City | Form 990-N | No figure |
| Wheaton Rotary Service FundWheaton | Form 990-EZ | $37,432FY2025 |
| Chicago Jewish Historical SocietyChicago | Form 990-N | No figure |
| Illionis Congress of Parents TeachersRiverside | Form 990-EZ | $37,188FY2024 |
| Riverside-Brookfield High School Educational FoundationRiverside | Form 990-N | No figure |
| Habitat for Humanity International IncQuincy | Form 990 | $37,108FY2024 |
| Lincoln Douglas SocietyFreeport | Form 990-N | No figure |
| Wish Upon a StarJoliet | Form 990-EZ | $36,922FY2024 |
| Piatt County Toy & Gift Program IncMonticello | Form 990-N | No figure |
| Central Illinois Downs Syndrome OrganizationNormal | Form 990-N | No figure |
| Polish Genealogical SocietyChicago | Form 990-N | No figure |
| International Society of AutomationNew Lenox | Form 990-EZ | $36,589FY2026 |
| Illinois Congress of Parents TeachersWestern Springs | Form 990-EZ | $36,362FY2025 |
| Self Help Jobs ProgramTinley Park | Form 990-N | No figure |
| Parent-Teacher Organization of Countryside SchoolBarrington | Form 990-EZ | $35,924FY2026 |
| Life Force Arts Foundation IncChicago | Form 990-N | No figure |