| City Exchange Company WLL | Financial Services |
| City Media | Media |
| Civil Aviation Authority - Qatar | Governmental Institutions |
| CLASSIC DOME | Construction |
| Cleopatra Trading & Contracting Company | Construction |
| Cleopatra Travels | Leisure and Tourism |
| Coastal Qatar | Conglomerates |
| Coastal Trading & Engineering Company W.L.L | Construction |
| Cofely Besix Mannai Facility Management LLC | Real Estate |
| Collaborative Endeavour Contracting Co WLL | Conglomerates |
| College of the North Atlantic - Qatar | Education |
| Colors & More | Media |
| Commercial Bank Financial Services (L.L.C.) | Financial Services |
| Commitement Engineering Works | Construction |
| COMMITMENT ENGG. WORKS | Construction |
| Commodore Qatar Contracting Company L.L.C. | Construction |
| Communications Regulatory Authority | Governmental Institutions |
| Computer Arabia W.L.L. | Information Technology |
| Computer World | Conglomerates |
| Concorde Hotel Doha | Leisure and Tourism |
| Confidence Engineering and Development Company | Construction |
| ConocoPhillips Qatar Ltd | Oil and Gas |
| Conserved Foodstuffs Distribution Company W.L.L. | Food and Beverages |
| Consolidated Gulf Company | Information Technology |
| Construction Commissioning Maintenance Services WLL | Construction |
