Section F-1 of Alpha Phi Omega is Western side of central Illinois, and includes these chapters/extension groups:
- Zeta Alpha at Bradley University
- Eta Sigma at Illinois College
- Lambda Rho at Augustana University
- Alpha Beta Gamma at Knox College
Section F-2 of Alpha Phi Omega is the northern quarter of Illinois (except Chicago and Evanston) along with the northwest corner of Indiana, and includes these chapters/extension groups:
- Eta at Northern Illinois University
- Zeta Gamma at Valparaiso University
- Alpha Beta Omicron at Elmhurst College
- Alpha Zeta Delta at Lake Forest College
Section F-3 of Alpha Phi Omega is Eastern side of central Illinois, and includes these chapters/extension groups:
- Alpha Alpha at the University of Illinois at Urbana-Champaign
- Eta Epsilon at Millikin University
- Theta Epsilon at Illinois State University
- Omega Epsilon at Illinois Wesleyan University
- Alpha Zeta Omega at Parkland College
- Alpha Eta Lambda at Eureka College
Section F-4 of Alpha Phi Omega is Chicago and Evanston, and includes these chapters/extension groups:
- Sigma at Northwestern
- Pi Eta at Loyola University
- Gamma Sigma at the University of Chicago
- Sigma Sigma at the University of Illinois at Chicago
- Upsilon Iota at DePaul University
