| T4U Co., Ltd | Tokyo |
| Tab Solution Co., Ltd | Tokyo |
| Tabuchi Electric Co., Ltd | Tokyo |
| Tacchi Studios | |
| TACSYSTEM Co., Ltd | Tokyo |
| TAGCYX Biotechnologies Co., Ltd | Tokyo |
| Taichii Electric Cable Co., Ltd | Tokyo |
| Taiho Pharmaceutical Co., Ltd | |
| Taima Art University | |
| Taisei Gakuin University | |
| Taisho Pharmaceutical Co., Ltd | |
| Taisho University | Tokyo |
| Taiyo Cabletec Corporation | |
| Taiyo Electric Co., Ltd | |
| Taiyo Holdings Co., Ltd | Tokyo |
| Taiyo Koki Co., Ltd | |
| Taiyo Yuden Co., Ltd | Tokyo |
| TAK Co., Ltd | Gifu |
| Takachiho University | |
| Takada Junior College | |
| Takagi Connect Corporation | |
| Takahashi Seiki Co., Ltd | |
| Takamatsu University | |
| Takaoka Cable Networks Co., Ltd | Toyama |
| Takara Bio, Inc. | |
| Takarazuka University | |
| Takarazuka University of Medical and Health Care | |
| Takasago Denki Cogyo Corporation | |
| Takasago Fluidic Systems | |
| Takasaki City University of Economics | |
| Takasaki University of Commerce & Junior College | |
| Takasaki University of Health and Welfare | |
| Takayama College | |
| Takeda Pharmaceutical Co., Ltd | |
| Takumi Information Technology Co., Ltd | Tokyo |
| Takushoku University | Tokyo |
| TAM, Inc. | Tokyo |
| Tama Software Co., Ltd | Tokyo |
| TAMA University | |
| Tamada Educational Institution | |
| Tamagawa Academy & University | |
| Tanaka System Planning Co., Ltd | Tokyo |
| Tanuki Software Ltd | Tokyo |
| Taoke Co., Ltd | Tokyo |
| Tas Co., Ltd | Tokyo |
| Tatsua Electric Wire & Cable Co., Ltd | Osaka |
| Tazmo Co., Ltd | Okayama |
| TB Innovations Ltd | |
| TBM Co., Ltd | |
| TBS Innovation Partners, LLC | |