| Acronym | Meaning |
| TON | Threshold Odor Numbers |
| TON | Turnover No. Of The Reaction |
| TOP | Trioctyl Phosphate |
| TOPO | Trioctylphosphine Oxide |
| TOPSE | Tropospheric Ozone Production About The Spring Equinox |
| TOR | Tropospheric Ozone Research |
| TOSS | Total Suppression Of Sidebands |
| TOST | Turbine Oil Stability Test |
| TOTE | Tropical Ozone Transport Experiment |
| TOVS | TIROS Operational Vertical Sounder |
| TOW | Time Of Wetting |
| TOX | Total Organic Halide |
| TOXFP | Total Organic Halide Formation Potential |
| TOXLINE | Toxicology Information Online (NLM) |
| TOXLIT | Toxicology Literature From Special Sources (NLM) |
| TOXNET | Toxicology Network Of The National Library Of Medicine |
| TPA | Tissue Plasminogen Activator |
| TPA | Terephthalic Acid |
| TPA | Two-photon Absorption |
| TPAD | Temperature Programmed Ammonia Desorption |
| TPAD | Temperature-phased Anaerobic Digestion |
| TPCA | Toxic Pit Cleanup Act (of California |
| TPCF | Two-point Correlation Function |
| TPD | Temperature Programmed Desorption (for Gas Chromatography) |
| TPDE | Temp.-programmed Decompn. |
| TPE | Thermoplastic Elastomer |
| TPE | Thermoplastic Polyester Elastomer |
| TPE | Threshold Photoelectron |
| TPEPICO | Threshold Photoelectron-photoion Coincidence |
| TPH | Total Petroleum Hydrocarbons |
| TPLSM | Two-photon Laser-scanning Microscopy |
| TPM | Two-potential Model (in At. Scattering Calcns.) |
| TPMB | Two-potential-modified Born (approxn. In Inelastic Collisions) |
| TPN | Total Parenteral Nutrition |
| TPO | Technical Project Officer |
| TPO | Temperature-programmed Oxidiation |
| TPO | Thermoplastic Polyolefin |
| TPOT | Two-parameter Omega Technique |
| TPP | Triphenyl Phosphate |
| TPPE | Two-photon Photoemission |
| TPPI | Time Proportional Phase Increment |
| TPPM | Two-pulse Phase Modulation |
| TPQ | Threshold Planning Quantity |
| TPR | Total Population Risk |
| TPR | Temperature-programmed Reduction |
| TPR | Tetratricopeptide Repeat |
| TPRRS | Transient Photoinduced Resonant Raman Scattering |
| TPRS | Temperature Programmed Reaction Spectrometry |
| TPSA | Topological Surface Area |
| TPSA | Total Prostate Specific Antigen |