- Cleveland Postal Employees Credit Union
- Cleveland Regional Medical Center
- Cleveland State University
- Clever Consultants, LLC
- Clever-Brooks, Inc.
- Click Shot Inc.
- Client Systems
- Clientlogic
- Clifton Springs Hospital and Clinic
- Clifton-Fine Hospital
- Clin Plus
- Clinch Memorial Hospital
- Clinch Valley Medical Center
- ClinForce
- Clinica Adelante, Inc.
- Clinica Espanola, Inc.
- Clinica Sierra Vista
- Clinical Computing, Inc.
- Clinical Marketing Consortium
- Clinical Solutions
- Clinical Trial Services
- Clinimetrics
- Clinton County United Way
- Clinton Memorial Hospital
- Clinton National Bank
- Cloud County Health Center
- Clovis Community Medical Center
- Clow Valve Co
- Club Corp.
- Club del Barrio, El
- CM Beavan Associates
- CMA
- CMC Americas Inc.
- CMC Electronics
- CMH Specialized Transportation, Inc.
- CMI Communications
- CNC-Access, Inc.
- CNS Healthcare
- Coal County General Hospital
- Coalition for Natural Health Inc.
- Coalition for the Homeless of Central Florida, Inc.
- Coast Independent Review Board
- Coast Plaza Hospital
- Coastal Bank
- Coastal Carolina Health Alliance
- Coastal Fairfield County Convention and Visitors Bureau
- Coastal Health District of Georgia
- Coastal Health Systems of Brevard, Inc.
- Coastal Hotel Group
- Coastal Printing, Inc. of Sarasota