| Tego Science | |
| TektonSpace, Inc. | Seoul |
| Telechips, Inc. | Seoul |
| Telecommunications Technology Association | Gyeonggi |
| Telos, Inc. | |
| Tencent Korea Ltd | Seoul |
| Tenspace | Seoul |
| TES Co., Ltd | Gyeonggi |
| The Cell Co., Ltd | Gyeonggi |
| the DIGILOG | Seoul |
| The Invention Lab | Seoul |
| The Koreal Economic Daily | |
| The Korean TeX Society | Seoul |
| The Pinkfong Company | Seoul |
| The Swing Co., Ltd | |
| Therabest | |
| TheraSid Bioscience | |
| Therazyne Co., Ltd | |
| Thewebstyle | Seoul |
| THINKmarine Co., Ltd | Seoul |
| Thira-Utech Co., Ltd | Seoul |
| Thomas Engineering Company | |
| TiCARos | |
| TiumBio | Gyeonggi |
| TK101 Global | Seoul |
| TKC Global Technology | Gyeonggi |
| TmaxGroup | Seoul |
| TmaxSoft | Seoul |
| TMC Co., Ltd | South Chungcheong |
| TocPlus | Seoul |
| Todos | |
| Tokai Carbon Korea Co., Ltd | Gyeonggi |
| Tongmyong University | Busan |
| Tongwon University | |
| ToolGen, Inc. | Seoul |
| TOP Engineering Co., Ltd | |
| Top Management Consulting Co., Ltd | Seoul |
| Topfield Co., Ltd | Gyeonggi |
| Torch Trinity Graduate University | |
| Toss | Seoul |
| Touch Cash Co., Ltd | Seoul |
| TourOffice | |
| Towen | |
| Travel Code Co., Ltd | Seoul |
| Tridge | |
| Trigem Computer, Inc. | Gyeonggi |
| TriOar | |
| TRUEWEB Co., Ltd | Seoul |
| TrustKey Solutions, Inc. | Seoul |
| TSE Co., Ltd | South Chungcheong |