| tlm | Timeline Maker Timeline Data |
| tln | HyperLynx LineSim Schematic |
| tlo | SPSS Table Look File |
| tlog | ArduCopter Telemetry Log |
| tlog | Oracle Database Transaction Log |
| tlr | Tableau Offline License Registration Data |
| tlst | GibbsCAM Tool List Data |
| tlsv | Topcon TopSURV Database |
| tlt | AVerMedia AVerTV Go Teletext Data |
| tlt | Topocad Line Table Data |
| tlt | Trellix Web Design Template |
| tlv | TruLASER View Geometry Data |
| tlx | Cardbox User Spelling Dictionary |
| tlx | Catalyst Translation Toolkit Data |
| tlx | CuteSITE Builder Website Data |
| tlx | Technics SX-KN6000 Text Lyrics Data |
| tlx | Trellix Web Design Data |
| tly | Adobe Photoshop Elements Backup Catalog |
| tlz | LZMA Compressed TAR Archive |
| tlzma | LZMA Compressed TAR Archive |
| tm | Catalyst Translation Memory Data |
| tm | PCCharge Transaction Data |
| tm1 | TimeWise Data |
| tma | DCI TradeManager Catalog Archive |
| tmb | 602PC Suite Thumbnail Data |
| tmb | Movie Magic Screenwriter Timed Backup |
| tmblr | TumblRipper Data |
| tmbundle | TextMate Bundle |
| tmcommand | TextMate Command Data |
| tmd | TrueMap Surface Data |
