| Abbreviation | Definition |
|---|---|
| SOMI | Special Olympics Michigan |
| SONG | Small Organizations, Not Government |
| SOP | Seeds Of Peace |
| SOPHIE | Stamp Out Prejudice, Hatred Intolerence Everywhere |
| SOPHIE | Stamp Out Prejudice, Hatred & Intolerence Everywhere |
| SOPI | Seeds Of Peace, Inc. |
| SORB | Save Our Riverfront Bushland |
| SOS | Save Ontario's Shipwrecks |
| SOS | Save Oregon Shipwrecks |
| SOS | Save Our Shepherds |
| SOS | Save Our Streams |
| SOS | Save Outdoor Sculpture |
| SOS | Share Our Strength |
| SOS | Sisters Offering Support |
| SOS | South Oakland Shelter |
| SOS | Survivors Of Suicide |
| SOSC | Special Olympics of South Carolina |
| SOSCV | SOS Children's Villages |
| SOSD | Save Our Street Dogs |
| SOSF | Save Our Seals Fund |