| Technical Supplies & Services Co. W.L.L. | Transport |
| Techno Q | Telecommunications |
| Technochem Limited | Oil and Gas |
| Technology for Electrical Services and Contracting W.L.L | Construction |
| Technoserve W.L.L. | Information Technology |
| TECHNOWAVE LLC | Construction |
| TEM-AC Trading & A/C Contracting WLL | Construction |
| Temalco Contracting & Trading Company W.L.L | Construction |
| Tenpo Trading and Contracting Company W.L.L | Construction |
| TeraNet Technologies | Information Technology |
| Terratest Qatar International Drilling Group | Construction |
| Test & Measurement Solutions Ltd. WLL | Industrial Manufacturing |
| Texas A&M University at Qatar | Education |
| Teyseer Air Conditioning & Refrigeration Company WLL | Industrial Manufacturing |
| Teyseer Building Materials & Transport Company (W.L.L) | Industrial Manufacturing |
| Teyseer Industrial Supplies & Services Company W.L.L. | Industrial Manufacturing |
| Teyseer Motors WLL | Transport |
| Teyseer Service Centre | Transport |
| The Abdullah Bin Hamad Al-Attiyah International Foundation for Energy and Sustainable Development | Services |
| The Arab Architects | Construction |
| The Cambridge School | Education |
| The Commercial Bank (Q.S.C.) | Financial Services |
| The First Investor P.Q.S.C. | Financial Services |
| The Group Securities Company | Financial Services |
| The Industry Emporium QFC Branch | Services |
