- Crozer-Keystone Health System
- CRSA Inc.
- CRST, Inc.
- Crusader Community Health
- CRW
- CryoLife, Inc.
- Crystal Cream and Butter
- CSC - Correctional Services Corporation
- CSD
- CSEA Local 1000
- CSK Auto, Inc.
- CSR Group
- CSX Transportation
- CSXT
- CT Department of Motor Vehicles
- CTAM
- CTI
- CTR Systems Inc.
- Cub Scout Pack 194
- Cuba Memorial Hospital
- Cullman Regional Medical Center
- Culpepper Garden
- Culver Stockton College
- Culver's Frozen Custard
- Cumberland County Hospital
- Cumberland Medical Center
- Cumming Clinical Consulting, Inc.
- Cummins Atlantic, Inc.
- Cummins Engine Co., Inc.
- Cummins Filtration
- Cummins Inc.
- CUNA and Affiliates
- Curbell
- Curly's Foods
- Current Works, Inc.
- Curry County New Mexico
- Cushing Manufacturing Co
- Custer County
- Custom Pin and Design
- Customer One Mortgage
- Customs and Border Protections NTEU JFK Chapter 153
- Cuyahoga Community College
- Cuyahoga County Office of Health and Human Services
- Cuyuna Regional Medical Center
- Cvbtv.com-Zephyr Marketing
- Cvent.com
- CVI Laser Corporation
- CVS-Pharmacy
- Cy-Fair Houston Chamber of Commerce
- Cyber-Test Inc.