| ThinkPenny | |
| ThinkPod Agency | |
| ThinkRite | Florida |
| ThinkSecureNet, LLC | Delaware |
| ThinkSEM | Minnesota |
| ThinkSmart Software | District of Columbia |
| ThinkSmartPOS | Ohio |
| Thinkspace | Washington |
| Thinkstrategy | California |
| ThinkSys, Inc. | |
| ThinkTank Interactive | Georgia |
| Thinktiv, Inc. | Texas |
| ThinkToner.com | California |
| ThinkWare, Inc. | Ohio |
| thinkWeb, Inc. | Illinois |
| Thinkwell Corporation | Texas |
| Thinnect, Inc. | California |
| ThinPATH Systems, Inc. | Oregon |
| thinQ | North Carolina |
| ThinSpring | New Jersey |
| Thinsquare | |
| Thintronics | |
| Third Arc Bio | |
| Third Coast Marketing | Texas |
| Third Coast Systems | Texas |
| Third Door Media | Connecticut |
| Third Eye Health | Illinois |
| Third Eye Software, Inc. | Georgia |
| Third Harmonic Bio | California |
| Third Insight | Texas |
| Third Lane Technologies, LLC | California |
| Third Millennium, Inc. | Massachusetts |
| Third Partners, LLC | |
| Third Party International, Inc. | Oregon |
| Third Point Ventures | California |
| Third Point, LLC | |
| Third Pole, Inc. | Massachusetts |
| Third Rock Ventures | Massachusetts |
| Third Wave Analytics, Inc. | |
| Third Wave Business Systems | New Jersey |
| Third Wave Digital | Georgia |
| ThirdChannel | Massachusetts |
| Thirdera | |
| ThirdEye Data, Inc. | California |
| ThirdLaw Molecular, Inc. | |
| ThirdLine | |
| ThirdPacket Technologies | |
| ThirdPartyTrust, LLC | Massachusetts |
| Thirdshelf, Inc. | |
| ThirdSphere | |