| Acronym | Meaning |
| SHC | Selective Hydrophobic Coagulation |
| SHC | Symmetrized Hyperspherical Coordinates (in Quantum Calcns. On Reactive Scattering) |
| SHE | Standard Hydrogen Electrode |
| SHEBA | Surface Heat Budget Of Arctic Ocean |
| SHED | Sealed Housing For Evaporative Detn. |
| SHEED | Scanning High-energy Electron Diffraction |
| SHG | Second Harmonic Generation |
| SHIRE | Southern Hemisphere Infrared Experiment |
| SHIV | Simian-human Immunodeficiency Virus |
| SHM | Stockholm Humic Model |
| SHM | Screened Hydrogenic Model (for Electronic Structure In Plasmas) |
| SHOA | Second-harmonic Optical Activity |
| SHR | Selective Hybrid Reduction |
| SHR | Spontaneously Hypertensive Rat |
| SHREWD | Standoff Handheld Real-time Early Warning Detector |
| SHRIMP | Scalar Heteromolecular Recoupled Interactions By Multiple Phase |
| SHRIMP | Sensitive High Mass Resolution Ion Microprobe |
| SHRP | Strategic Highway Research Program |
| SHRS | Stimulated Hyper Raman Scattering |
| SHS | Self-propagating High-temperature Synthesis |
| SHT | Surface Hopping Trajectory (model For Mol. Scattering) |
| SI | Stieltje Imaging (method For Calcg. Wave Functions) |
| SI | Scale Index |
| SI | Site Investigation |
| SI | State Interaction Method |
| SI | Surface Ionization |
| SIA | Semiconductor Industry Association |
| SIA | Self-interstitial Atom |
| SIA | Sequential Injection Analysis |
| SIA | Stepwise Isothermal Analysis |
| SIAM | Society For Industrial And Applied Mathematics |
| SIAM | Single-impurity Anderson Model |
| SIBFA | Sum (of) Interactions Between Fragments (computed) Ab Initio |
| SIBS | Spark Induced Breakdown Spectroscopy |
| SIC | Self-interaction Correction (in Exchange-energy Calcns.) |
| SIC | Silicon Integrated Circuit |
| SIC | Standard Industrial Classification |
| SIC | Std. Industrial Code |
| SIC-GX-LSD | Self-interaction Corrected Generalized Exchange Local Spin Density |
| SICIMS | Selective Ion Chemical Ionization Mass Spectrometry |
| SICM | Scanning Ion-conductance Microscopy |
| SICP | Sealed Inductively Coupled Plasma |
| SID | Surface Ionization Detector |
| SID | Selected Ion Detection |
| SID | Surface Induced Dissociation |
| SIDAMS | Simultaneous Ion Detection In Atmospheric Mass Spectrometry |
| SIDLTS | Scanning Ion Deep Level Transient Spectroscopy |
| SIDMS | Speciated Isotope Dilution Mass Spectrometry |
| SIDP | Sputter Ion Depth Profiling |
| SIDS | Screening Information Data Set |