| Acronym | Meaning |
| MSG | Master Sergeant (US military) |
| MSG | Message |
| MSG | Maine State Government |
| MSG | Maintenance Support Group |
| MSG | Maintenance Support Guide Status |
| MSG | Manpower Scaling Guide (US DoD) |
| MSG | Marine Security Guard |
| MSG | Marine Strike Group (US DoD) |
| MSG | Massachusetts State Guard |
| MSG | Material Systems Group |
| MSG | Materiel Systems Group |
| MSG | Maximum Specific Gravity (paving mixture) |
| MSG | Microgravity Science Glovebox |
| MSG | Mikhail Sergeyevich Gorbachev (former USSR president and Nobel Peace Prize winner) |
| MSG | Militärisches Scharfschützen Gewehr (Heckler and Koch sniper rifle) |
| MSG | Ministère des Services Gouvernementaux (French: Ministry of Government Services) |
| MSG | Ministry of the Solicitor General (Canada) |
| MSG | Mission Support Group (USAF) |
| MSG | Missouri State Government (US) |
| MSG | Missouri State Guard |
| MSG | Modular Shelter, Underground |
| MSG | Multi-sectoral Group (Trinidad & Tobago) |