| Acronym | Definition |
|---|
| T3 | T-carrier 3 (digital transmission line, 44.736 Mbps, 672 voice channels) |
| T3 | Terminator 3 (movie) |
| T3 | Triiodothyronine (thyroid hormone) |
| T3 | Typo3 (content management framework) |
| T3 | Train the Trainer |
| T3 | Tomorrow's Technology Today |
| T3 | Topological Space (mathematics; topology) |
| T3 | Third Thoracic Segment (insects) |
| T3 | Technical Training by Telephone |
| T3 | Tengah 3 (protocol/clients) |
| T3 | Twin Threaded Technology (Velomax wheels) |
| T3 | Technical Team Training |
| T3 | Teach to Teachers |
| T3 | Tri-Band Tactical Terminal |
| T3 | Traffic Training Team (Baltimore County Police) |