MSOS
| Acronym | Definition |
|---|---|
| MSOS | Multi Service over Sonet |
| MSOS | Multiple Systems Operators |
| MSOS | Medication Safety Officers Society (formerly American Society of Medication Safety Officers) |
| MSOS | Manitoba Society of Seniors (est. 1979; Canada) |
| MSOS | Marine Special Operations School (US Marine Corps) |
| MSOS | Mouse Son of Sevenless (genetics) |
| MSOS | Mass Storage Operating System |
| MSOS | Mammalian Son of Sevenless (gene) |