- Orlando Health Horizon West
- Orlando Health South Seminole Hospital
- Orlando Health St. Cloud Hospital
- Orlando Orange County Convention and Visitors Bureau
- Orlando Regional Chamber of Commerce
- Orlando Regional Medical Center
- Orlando Union Rescue Mission
- Orlando VA Medical Center
- Orlando-International Drive - Fairfield Inn by Marriott, FL
- Orlando-Orange County Convention and Visitors Bureau, Inc.
- Orlando-South - Fairfield Inn by Marriott, FL
- Orleans-Niagara BOCES
- Oro Valley Hospital
- Oroville Hospital
- Orrville Area United Way, Inc.
- Orthopaedic Research Society
- Orthopedic Specialty Hospital of Nevada
- OrthoVirginia
- Orzark Tri-County Healthcare Consortium
- Osceola Community Hospital, Inc.
- Osceola County Co-Op Oil Co.
- Osceola County Sheriff's Office
- Osceola Regional Health Center
- Osceola Regional Medical Center
- Oscient Pharmaceuticals
- OSF Center for Health - Streator
- OSF Center for Health - Streator
- OSF Center for Health - Streator
- OSF Healthcare Saint Paul Medical Center
- OSF Heart of Mary Medical Center
- OSF Holy Family Medical Center
- OSF Holy Family Medical Center
- OSF Little Company of Mary Medical Center
- OSF Medical Group - Ottawa
- OSF Sacred Heart Medical Center
- OSF Saint Anthony Medical Center
- OSF Saint Anthony Medical Center
- OSF Saint Clare Medical Center
- OSF Saint Elizabeth Medical Center
- OSF Saint Elizabeth Medical Center
- OSF Saint Francis Medical Center
- OSF Saint James - John W. Albrecht Medical Center
- OSF Saint James - John W. Albrecht Medical Center
- OSF Saint James- John W. Albrecht Medical Center
- OSF Saint Joseph Medical Center
- OSF Saint Luke Medical Center
- OSF Saint Mary Medical Center
- OSF Saint Paul Medical Center
- OSF St. Mary Medical Center
- OSI