- Carl Albert Community Mental Health Center
- Carnegie Tri-County Municipal Hospital
- Carrus Lakeside Hospital
- Cedar Ridge Behavioral Hospital
- Childrens Recovery Center of Oklahoma
- Choctaw Memorial Hospital
- Cimarron Memorial Hospital
- Cleveland Area Hospital
- Clinton Regional Hospital
- Coal County General Hospital
- Comanche County Memorial Hospital
- Cordell Memorial Hospital
- Cornerstone Specialty Hospitals Broken Arrow
- Cornerstone Specialty Hospitals Muskogee
- Cornerstone Specialty Hospitals Shawnee
- Council Oak Comprehensive Health Care