| Construction Dynamics LLC | Construction |
| Consulting Engineering Group | Construction |
| Container Freight Station | Conglomerates |
| Contraco WLL | Construction |
| Contrade Company Trading and Contracting | Construction |
| Control Contracting & Trading Co. (Pvt.) Qatar | Conglomerates |
| Contromet W.L.L | Construction |
| Convert Engineering & Trading | Construction |
| Conxion Logistics & Heavy Equipments | Transport |
| COREO | Real Estate |
| Country Rent A Car | Transport |
| Cozmo Travel Qatar | Leisure and Tourism |
| Creative Action Design LLC | Services |
| Creative Rent A Car & Transport, Trading Co WLL | Conglomerates |
| Creo Co | Power and Utilities |
| Crompton International Trading & Contracting Company W.L.L. | Construction |
| Crown Group | Industrial Manufacturing |
| Crown Trading & Contracting Company | Industrial Manufacturing |
| Crystal Food Oil Qatar | Oil and Gas |
| CUT TECH Trading & Contracting | Construction |
| Dados Beauty | Services |
| Daien | Conglomerates |
| Dallah Advertising Agency | Services |
| Dallah International Catering & Trading | Retail |
| Damaan Islamic Insurance Company "Beema" (Q.S.C.C) | Financial Services |
