| Acronym | Definition |
|---|
| MAS | Maintenance Action Sheet |
| MAS | Malaysian Airlines System (ICAO code) |
| MAS | Managed Access System (prison technology) |
| MAS | Maneuver Air Support |
| MAS | Maneuver Ammunition Systems (US DoD) |
| MAS | Manitoba Affidavit of Support (Canada) |
| MAS | Mapping Activity Statement (US FEMA) |
| MAS | Maritime Assistance Service (International Maritime Organization) |
| MAS | Maryland Adolescent Survey (Maryland State Department of Education) |
| MAS | Master Assembly Schedule |
| MAS | Medical Aid Scheme (various locations) |
| MAS | Memorial Affairs Squadron |
| MAS | Metro Animal Services (various locations) |
| MAS | Metropolitan Ambulance Service (Melbourne, Australia) |
| MAS | Military Aftermarket Services |
| MAS | Military Agency for Standardization |
| MAS | Military Aid Society |
| MAS | Military Air Solutions (now Military Air & Information; UK) |
| MAS | Military Air System (Eastern Air Defense Sector) |
| MAS | Military Airlift Squadron |
| MAS | Military Application Seminar |
| MAS | Military Assistance Sales |
| MAS | Minimum Acceptable Strength |
| MAS | Mission Aircrew School |
| MAS | Mission Area Summary |
| MAS | Mission d'Amenagement du Delta du Fleuve Senegal |
| MAS | Modern Apprenticeship Scheme |
| MAS | Monetary Authority of Singapore |
| MAS | Motoscafo Anti Sommergibile (Italian navy WWI and WWII) |
| MAS | Motoscafo Armato Silurante (Italian: Torpedo Armed Motorboat) |
| MAS | Multiple Address Spectrum (FCC) |