| sot | Adventure SOS Walkthrough Source |
| sou | WRAP Simulation Results Output Data |
| soundpack | SoundPackager Sound Package |
| sov | 3DCS Advanced Analyzer/Optimizer SOVA Model |
| sox | BiRT Spreadsheet Report Executable File |
| sp | SignPlot Document |
| sp | Simplexety Parameter File |
| sp | STK Sensor Pointing File |
| sp3 | NGS Standard Product 3 Format Data |
| spa | MikuMikuDance Sphere Mapping File |
| spbm | VMware vSphere Storage Policy Based Management Data |
| spc | Microsoft Software Publisher Certificate |
| spc | Thermo Scientific SPC File |
| spcmd | Stereoscopic Player Commands Data |
| spd | SpecTRM Specification |
| spd | SPSD/M Database |
| spd | Form Z Suspended Rendering FIle |
| spd | Windows Server Security Policy Database |
| spda | Surveyor PDA Detector Data |
| spdata | Microsoft SharePoint Project Data |
| spdb | iGO Primo SpeedCam Database |
| spdnv | Spreadtrum NV Backup |
| spe | SPSS Extension |
| speccy | Speccy Snapshot Data |
| spef | Standard Parasitic Exchange Format |
| spentry | Spartan Entry Database |
| spex | SPEX Data |
| spexp | Substance Painter Export Preset Data |
| spf | SQR Portable Format |
| spfs | Spider File Storage |
