| T&D | Transmission and Distribution |
| T | Tera (10^12) |
| t | Time in seconds |
| T | Torque |
| T | Transformer |
| TAB | Technical Advisory Board |
| TACS | Total Access Communication System |
| TAFF | Thermally Activated Flux Flow |
| TAP | Tool Application Program |
| TAS | Trace analysis system |
| TAT | Turnaround time |
| TAX | Trunk Automatic Exchange |
| TB | Tight Binding |
| TBC | Time-based competitiveness |
| TC | Time constant; temperature coefficient |
| TC | ThermoCouple; Time Compression; Temperature Cycle |
| TCA | Test Calibration Assembly |
| TCAD | Technology computer-aided design |
| TCC | Tactical Cell Controller; Temperature Coefficient of Capacitance |
| TCDM | Tool development cost model |
| TCE | Temperature Coefficient of Expansion |
| TCI | Tele-Communications, Inc |
| TCM | Tunneling current microscopy |
| TCN | Transparent Content Negotiation |
| TCO | Total Cost of Ownership |
| TCP | Transfer Call Protocol |
| TCP | Transformer-Coupled Plasma; Tape Carrier Package |
| TCP | Transmission Control Protocol |
| TCP/IP | Transmission Control Protocol/Internet Protocol |
| TCR | Temperature Coefficient of Resistance |
| TCS | Temperature Coefficient Sensitivity |
| TCXO | Temperature Compensated Crystal Oscillator |
| TD | Thermal Donor(s); Thermal desorption |
| TDD | Time Division Duplex |
| TDDB | Time-dependent dielectric breakdown |
| TDEV | Transport-level deviation |
| TDM | Time Division Multiplexing |
| TDMA | Time Division Multiple Access |
| TDMS | Thermal Desorption Mass Spectrometry |
| TDR | Time-Domain Reflectometry |
| TD-SCDMA | Time Division Synchronous Code-Division Multiple-Access |
| TE | Tail End; Transmitted Electron |
| TE | Transverse electric |
| TEA | Transverse excited atmosphere |
| TEC | Thermal expansion coefficient; Test and Electrical Characterization; Thermo electric coolers |
| TECAP | Transistor electrical characterization and analysis program |
| TED | Transient enhanced diffusion; transmitted electron detection |
| TEG | Technical exchange group |
| TEGFET | Two-dimensional Electron Gas Field-Effect Transistors |
| TEM | Transmission Electron Microscopy; Tunneling Electron Microscopy; Transverse ElectroMagnetic mode |
| TES | Two Electron Satellite |
| TFC | Total Fault Coverage; Thin Film Capacitor |
| TFE | Tetrafluorethylene (teflon) |
| TFED | Thin Film Electroluminescent Display |
| TFMSL | Thin Film Micro Strip Line |
| TFN | Thin Film Network |
| TFR | Terrain Following Radar; Thin Film Resistor |
| TFT | Thin Film Transistor |
| TFX | Toxic effects |
| TGA | Thermal gas analysis; TrueVision Targa image format |
| TH | Through hole |
| THC | Total hydrocarbons |
| THEED | Transmission High Energy Electron Diffraction |
| THT | Two Hole Transition; Through hole technology |
| TIF | Tagged Image File image format |
| TIFF | Tag Image File Format |
| TIR | Total indicator runout; Total internal reflection |
| TIS | Tool induced shift |
| TLC | Thin layer chromatography |
| TLE | Tool loading elevator |
| TLM | Tape-laying machine; Telemeter; Transition line model |
| TLS | Transport Layer Security |
| TLV | Threshold limit value |
| TLV/TWA | Threshold limit value/time-weighted average |
| TM | Transport Module; Transition Metal |
| TM | Transverse magnetic |
| TMA | Thermo mechanical analyzer; |
| TMC | Transport module controller; Transfer module controller |
| TML | Total mass loss |
| TMO | Telegraphic Money Order |
| TNC | Threaded Neill Concelman connector |
| TO | Transistor outline package |
| TOA | Take-off angle |
| TOC | Total organic carbon; Total oxidizable carbon |
| TOI | Third Order Intercept |
| TOP | Technical and Office Protocol |
| TP | True position |
| TPD | Temperature program desorption |
| TPG | Test pattern generation |
| TPM | Total Productive Maintenance; Total Productive Manufacturing |
| TPMS | Tire Pressure Monitoring System |
| TPMS | Tyre Pressure Monitoring Sensors |
| TPRS | Temperature programmed reaction spectroscopy |
| TPU | Thermal processing unit |
| TQ | Total quality |
| TQFP | Thin Quad Flat Pack |
| TQM | Total Quality Management |
| TR | Transmit-receive |
| TRACT | Transportable Remote Area Communications Terminal |
| TRF | Transition Reflection Formalism |
| TRIM | Transport of Ions in Matter |
| TRL | Through Reflect Line |
| TRON | The Realtime Operation System Nucleus |
| TS | Transport Stream |
| TSC | Thermally Stimulated Current |
| TSCA | Toxic Substances Control Act |
| TSCAP | Thermally Stimulated CAPacitance |
| TSFZ | Traveling Solvent Floating Zone |
| TSI | Time Slot Interchanger |
| TSOP | Thin Small Outline Package |
| TSP | Temperature-sensitive parameter |
| TSSOP | Thin Shrink Small Outline Package |
| TT | Technology trasnsfer |
| TTA | Telecommunications Technology Association |
| TTC | Telecommunication Technology Committee |
| TTD | True Time Delay |
| TTL | Transistor-transistor logic |
| TTL | Through the lens |
| TTV | Total thickness variation |
| TV | Tele Vision |
| TVAC | Thermal VACuum (chamber) |
| TVRO | TV Receive Only |
| TVS | Triangular voltage sweep |
| TWA | Time-weighted average |
| TWG | Technical Working Group |
| TWT | Traveling wave tube |
| TXRF | Total X-ray fluorescence |
| T/C | Thermocompression |
| T/S | ThermoSonic |
| T1 | 1,544 Mb/s |
| T3 | 44,736 Mb/s |
| Ta | Tantalum |
| temp | Temperature |
| tera | 10^12 |
| THz | Terahertz |
| T-M | Time-to-market |
| ToD | Time of Day |
| ToR | Top of range |
| ToS | Type of Service |
| TOW | Tube-launched, Optical-tracked, Wire-guided (Missile) |
