| Trey Trading & Contracting Company W.L.L | Construction |
| TRIGON INTERNATIONAL W.L.L | Industrial Manufacturing |
| Triple Two | Services |
| Troy Engineering WLL | Conglomerates |
| Trust Exchange Company | Financial Services |
| Tutis Training & Consultancy | Education |
| Twafique Trading & Contracting W.L.L. | Services |
| UAQ Safety & Consultancy | Education |
| UCT Cleaning & Trading Co. W.L.L | Conglomerates |
| Ultimate International Trading | Construction |
| Ultimate Trading and Contracting Company W.L.L | Construction |
| Unified Electromecanical LLC | Construction |
| Unified Electromechanical WLL | Conglomerates |
| Unigulf Trading & Contracting | Conglomerates |
| Union National Bank - Qatar | Financial Services |
| Uniplast Company | Industrial Manufacturing |
| Unique Rent A Car | Transport |
| Unique Trading W.L.L | Industrial Manufacturing |
| United Brothers Trading & Contracting WLL | Construction |
| United Building DCTC WLL | Construction |
| United Construction Est. | Construction |
| United Consultants | Construction |
| United Development Company Q.P.S.C | Real Estate |
| United East Project W.L.L | Construction |
| United Electromechanical International Est. | Construction |
