S4
| Acronym | Definition |
|---|---|
| S4 | Secondary 4 (various locations) |
| S4 | Supply Officer (Army) |
| S4 | Sleep Mode 4 (hibernation computer sleep mode) |
| S4 | Stainless Sanitary Space System |
| S4 | Logistics/Embark Office (USMC) |
| S4 | Supersonicsoundscapes (event promotions/record store) |
| S4 | NATO SG/2 Shareable (Fire Control) Software Suite |