| tlm | Spektrum DX8 Telemetry Log |
| tln | HyperLynx LineSim Schematic |
| tlo | SPSS Table Look File |
| tlog | ArduCopter Telemetry Log |
| tlog | Oracle Database Transaction Log |
| tlr | Tableau Offline License Registration Data |
| tlsv | Topcon TopSURV Database |
| tlt | Trellix Web Design File |
| tlx | CuteSITE Builder Website Data |
| tly | Adobe Photoshop Elements Backup Catalog |
| tm | Catalyst Translation Memory Data |
| tm1 | TimeWise Data |
| tma | DCI TradeManager Catalog Archive |
| tmblr | TumblRipper Data |
| tmd | TrueMap Surface Data |
| tmdb | TaskMerlin Database |
| tme | Bryce Time Data |
| tmg | The Master Genealogist Data |
| tml | DB/TextWorks Thesaurus Maintenance Lock |
| tmm | TimeMap Metadata |
| tmn | Tmin Input File |
| tmpl | Xfire User Interface Template |
| tmq | TestMaster Questions Data |
| tmr | Free Countdown Timer Backup File |
| tms | Tableau Map Source |
| tmtheme | TextMate Theme |
| tmw | Translation Memory Data |
| tmx | Tiled Tile Map XML |
| tmy | Typical Meteorological Year Data |
| tmz | Medigraph Compressed Database |
