| Acronym | Meaning |
| SRT | Sludge Or Solids Retention Time |
| SRTC | Savannah River Technology Center |
| SRU | Soil Remediation Unit |
| SRXFA | Synchrotron Radiation X-ray Fluorescence Analysis |
| SRXPS | Spin-resolved X-ray Photoelectron Spectroscopy |
| SRXRF | Synchrotron Radiation X-ray Fluorescence |
| SS | Sewage Sludge |
| SS | Space Station |
| SS | Split-shell (gaussian Basis Set) |
| SS | Stainless Steel |
| SS | Suspended Solids |
| SS-CCSD | State Selective-CCSD |
| SS-MR-CC | State-selective Multireference Coupled-cluster |
| SS-OFMSW | Source Sorted Organic Fraction Of Municipal Solid Waste |
| SSA | Specific Surface Area |
| SSA | Spherical Sector Analysis |
| SSAO | Semicarbazide-sensitive Amine Oxidase |
| SSB | Semiclassical Sudden Born (approxn. In Ion-atom Collisions) |
| SSC | Superconducting Super Collider |
| SSC | Standard Saline Citrate |
| SSC | Sudden Storm Commencement (magnetic Storm) |
| SSC | Sulfide Stress Cracking |
| SSCAD | Spherical Self-consistent Atomic Deformation |
| SSCP | Single-strand Conformation Polymorphism |
| SSCP | Static Screened Coulomb Potential |
| SSCPA | Single-site Coherent-potential Approximation |
| SSCV | Semi-submersible Crane Vessel |
| SSD | Solid State Detector |
| SSDW | Static-static Distorted-wave (method) |
| SSE | Spinless Salpeter Equation |
| SSED | Solar System Exploration Division (NASA) |
| SSER | Spinless Salpeter Equation (with) Retardation |
| SSF | Slow Sand Filtration (water Treatment) |
| SSF | Synchronous Scanning Fluorescence |
| SSF | Space Station Freedom |
| SSFDC | Solid-state Floppy-disk Card (SmartMedia) |
| SSFLC | Surface-stabilized Ferroelec. Liq. Crystals |
| SSFP | Steady-state Free-precession |
| SSGF | Self-consistent Surface Green Function |
| SSH | Su-Schieffer-Heeger (model Hamiltonian For Electronic-structure Calcns.) |
| SSH | Suppressive Subtraction Hybridization |
| SSHF | Spin-symmetrized Hartree-Fock (wave Function) |
| SSIMS | Static Secondary Ion Mass Spectrometry |
| SSIP | Solvent-separated Ion Pair |
| SSIS | Scanning Surface Inspection System |
| SSL | Spent Sulfite Liquor |
| SSLP | Single-sequence Length Polymorphism |
| SSM | Synthetic Soil Matrix (US EPA) |
| SSMBE | Solid Source Molecular Beam Epitaxy |
| SSME | Space Shuttle Main Engine |