| Acronym | Meaning |
| TIMS | Thermal Ionization Mass Spectrometry |
| TIP | Temperature-independent Paramagnetism |
| TIP | Total Isomerization Process |
| TIPS | Technical Information Packages |
| TIPS | Transferable Intermol. Potential Functions |
| TIRF | Total Internal Reflectance Fluorescence |
| TIRFCS | Total Internal Reflection Fluorescence Correlation Spectroscopy |
| TIRFM | Total Internal Reflection Fluorescence Microscopy |
| TIRM | Total Internal Reflection Microscopy |
| TIROS | Television And IR Observation Satellite |
| TISAB | Total Ionic Strength Adjustment Buffer (for Fluoride) |
| TIU | Technical Information Unit |
| TIW | Time-independent Wave Packet |
| TIWLS | Time-independent Wave Packet Lippmann-Schwinger (equation) |
| TIWSLS | Time-independent Wave Packet Schroedinger (and) Lippmann-Schwinger (equation) |
| TKN | Total Kjeldahl Nitrogen |
| TLA | Thin Layer Activation |
| TLC | Thin-layer Chromatography |
| TLCP | Thermotropic Liquid Crystal Polymer |
| TLD | Thermoluminescent Dosimeter |
| TLDA | Total Lifetime Distribution Analysis |
| TLE | Temporal Lobe Epilepsy |
| TLEED | Tensor Low-energy Electron Diffraction |
| TLEV | Transition Low Emission Vehicle |
| TLFPE | Time-local Fokker-Planck Equation |
| TLHJ | Triple-layer Heterojunction |
| TLHS | Thin-layer Headspace |
| TLM | Triple Layer Model (of Adsorption) |
| TLM | Thermal Lens Microscopy |
| TLM | Transmission Line Method |
| TLP | Tension Leg Platform |
| TLP | Transient Liquid Phase |
| TLPS | Transient Liquid Phase Sintering [adhesive] |
| TLR | Toll-like Receptor |
| TLS | Thermal Lens Spectrometry |
| TLS | Two-level System (with Tunneling Transitions Between Wells Of Double-well Potential) |
| TLV | Threshold Limit Value |
| TM | Thematic Mapper (Remote Sensing) |
| TMA | Thermomagnetic Analysis |
| TMA | Tissue Microarray |
| TMA | Trimellitic Anhydride |
| TMA | Thermomechanical Analysis |
| TMA | Transcription-mediated Amplification |
| TMAFM | Tapping Mode Atomic Force Microscopy |
| TMAH | Tetramethylammonium Hydroxide |
| TMB | Table Mesa Basalt (USGS Rock Standard) |
| TMBP | Tin Mill Black Plate |
| TMC | Thick Molding Compound |
| TMC | Titanium Matrix Composite |
| TMC | Transition Metal Complex |