| ThinkTel Communications | Alberta |
| Thinkweb Media | Alberta |
| Thinkwise Solutions Ltd | Ontario |
| thinqINK | Alberta |
| Third Bridge | Quebec |
| Third Eye Designers | Ontario |
| Third Octet, Inc. | Ontario |
| Thirdstream | |
| This Game Studio | British Columbia |
| THNQ Global Corporation | |
| Thomas Craig Consulting | Prince Edward Island |
| Thomas Jono | British Columbia |
| Thompson Hall Digital, Inc. | |
| Thompson Rivers University | British Columbia |
| Thompson Rivers University - Department of Computing Science | British Columbia |
| Thompson Technologies, Inc. | |
| ThompsonStenning | |
| Thomson Reuters | |
| THORASYS Thoracic Medical Systems, Inc. | Quebec |
| Thorck | |
| Thorens Solutions | Quebec |
| Thornegate Consulting | Ontario |
| Thornely Falls | Ontario |
| Thorvin Electronics, Inc. | Ontario |
| Those Friggin Computers | Ontario |
| Thought Technology Ltd | Quebec |
| ThoughtFarmer | British Columbia |
| ThoughtStorm, Inc. | |
| ThoughtWire Corporation | Ontario |
| Thranite Corporation | Alberta |
| ThreatIQ, Inc. | |
| Three Marketing, Inc. | Manitoba |
| ThreeD Capital | |
| Threedify, Inc. | Ontario |
| ThreeShield Information Security Corporation | |
| Thriftking Computer | New Brunswick |
| Thrillworks, Inc. | Ontario |
| Thrive Digital | British Columbia |
| ThriveLine Web Design & SEO | |
| Thriver Technologies, Inc. | |
| Throne Computer Systems, Inc. | Ontario |
| Thrust Capital Partners | |
| Thumbprint Solutions, Inc. | Ontario |
| Thunder Graphics, Inc. | Manitoba |
| ThunderLotus | Quebec |
| Thundra Multimedia | |
| thynq3D | |
| TI Techno | Quebec |
| Ti-Shed-Informatique | |
| Tia Health | Ontario |