| Abbreviation | Definition |
|---|---|
| SPEF | Single Program Element Funding |
| SPERM | Social Political Economic Religious Military |
| SPETC | Solid Propellant Electro-thermal-Chemical |
| SPF | Single Project Funding |
| SPG | Self- Propelled Gun |
| SPG | Software Process Group |
| SPG | Special Patrol Group |
| SPG | Strategic Planning Guidance |
| SPG | Supplementary Planning Guidance |
| SPGH | Self-Propelled Gun Howitzer |
| SPHAWK | Self-Propelled HAWK |
| SPI | Schedule Performance Index |
| SPI | Sensor Point of Interest |
| SPI | Software Process Improvement |
| SPI | Special Inspection |
| SPI | Special Investigative (USAF) |
| SPI | Special Packaging Instruction |
| SPI | Standard Performance Indicator |
| SPI | Strategic Planning Initiative |
| SPIC | Spanish Person In Control |