| Acronym | Meaning |
| TMCP | Thermomech. Control Process |
| TMD | Transmembrane Domain |
| TMDL | Total Maximum Daily Load |
| TMDSC | Temperature-modulated Differential Scanning Calorimetry |
| TMFA | Three-mode Factor Analysis |
| TMIC | Toxic Materials Information Center |
| TMJ | Temporomandibular Joint |
| TMMC | Tetramethylammonium Manganese Trichloride |
| TMO | Truncated Molecular Orbital |
| TMOS | Tetramethyl Orthosilicate |
| TMP | Thermomechanical Pulping |
| TMP | Turbomolecular Pump |
| TMR | Tunneling Magnetoresistance |
| TMS | Transmission Moessbauer Spectroscopy ~ ~ |
| TMV | Thermal Modulation Voltammetry |
| TMV | Tobacco Mosaic Virus |
| TMWAM | Turkey-Mersey Watershed Acidification Model |
| TNA | Thermal Neutron Analysis |
| TNAA | Thermal Neutron Activation Analysis |
| TNBS | Trinitrobenzene Sulfonic Acid |
| TNF | Tumor Necrosis Factor |
| TNF | Tumor Necrosis Factor-alpha |
| TNFR | Tumor Necrosis Factor Receptor |
| TNFR1 | Tumor Necrosis Factor Receptor 1 |
| TNFSF | Tumor-necrosis Factor Superfamily |
| TNLCD | Twisted Nematic Liquid Crystal Display |
| TNN-TB | Third Neighbor Nonorthogonal (basis) Tight Binding |
| TNOA | Target Natural Orbital Approximation |
| TNRCC | Texas Natural Resource Conservation Commission |
| TNS | 6-p-Toluidino-2-naphthalenesulfonic Acid |
| TNVOX | Total Nonvolatile Org. Halogen Compds. |
| TO | Topological Orbital (in Graph Theory Of Molecules) |
| TO | Toxic Organic |
| TOA | Thermooptical Analysis |
| TOC | Total Organic Carbon |
| TOCOEN | Toxic Organic Compounds In The Environment (research Project In Czechoslovakia) |
| TOCSY | Total Correlation Spectroscopy |
| TOD | Theoretical Oxygen Demand |
| TOD | Total Oxygen Demand |
| TOF | Time Of Flight |
| TOF | Turnover Frequency |
| TOFA | Tall Oil Fatty Acids |
| TOFD | Time Of Flight Diffraction |
| TOFMS | Time Of Flight Mass Spectrometry |
| TOG | Total Organic Gas |
| TOGA | Tropical Oceans And Global Atmosphere |
| TOLED | Transparent Organic Light-emitting Diode |
| TOM | Total Organic Matter |
| TOM | Transition Operator Method |
| TOMS | Total Ozone Mapping Spectrometer |