| sar | Squeak Archive |
| sarc | Wii U SARC Archive |
| saz | Fiddler Session Archive Zip |
| sbb | Microsoft Accounting Backup |
| sbe | SafeBoot Encrypted Archive |
| sbkp | Ultimate Backup for BlackBerry Archive |
| sbsar | Substance Designer Archive |
| sbu | Samsung Kies Backup Archive |
| scz | SmartDraw Collection Package |
| sdn | Shareware Distributors Network |
| sea | StuffIt Expander Archive |
| seg1 | Stuffit Segment Data |
| seg2 | Stuffit Segment Data |
| seg3 | Stuffit Segment Data |
| segn | Stuffit Segment Data |
| sema | Secured EMail Archive |
| sen | Scifer Internal Header Archive |
| sfds | Single File Data Storage |
| sfu | Omnifi DMP1 System Firmware Update |
| sfz | SFzip SoundFont Compressed Archive |
| sgbzip | SaveGameBackup.net Archive |
| shar | Unix Shell Archive |
| shk | ShrinkIt Archive |
| shr | Unix Shell Archive |
| sidf | NBackup SIDF Backup Archive |
| sis | Psion Series 3 Software Package |
| sis | Symbian Install Package |
| sisx | Symbian Series 3 Install Package |
| sit | StuffIt Expander Archive |
| sit5 | StuffIt 5 Archive |
