| Abbreviation | Definition |
|---|---|
| SLR | Sweet Little Rifle |
| SLRP | Strategic Long Range Plan |
| SLRR | Sideways-Looking Reconnaissance Radar |
| SLS | Soft Landing System |
| SLT | Ship Letter Telegram |
| SLT | Slit |
| SLt | Sub-Lieutenant (Canadian Armed Forces) |
| SLTA | Small Laser Transmitter Assembly |
| SLTT | System-Level Technical Test |
| SLU | Sveriges Lantbruksuniversitet |
| SLV | Sleeve |
| SLW | Slew |
| SLWT | Side Loadable Warping Tug |
| SM | Salvage Mechanic |
| SM | Secretary, Joint Staff, Memorandum |
| SM | Selection Mechanism |
| SM | Service Manager |
| SM | Service Mode |
| SM | Sixteen Millimetre |
| SM | Spare part Management system |