| Acronym | Definition |
|---|
| MSS | Manuscripts |
| MSS | Managed Security Services (information security) |
| MSS | Maximum Segment Size (TCP/IP) |
| MSS | Mobile Satellite Services |
| MSS | Mass Storage System |
| MSS | Manufacturers Standardization Society |
| MSS | Multiple Sclerosis Society |
| MSS | Maxtor Shared Storage |
| MSS | Mission Support Squadron |
| MSS | Multi-Spectral Scanner |
| MSS | Merit System Services |
| MSS | Mobile Servicing System |
| MSS | Ministry of State Security (Chinese counterintelligence organization) |
| MSS | Management Support System |
| MSS | Maternal Serum Screening |
| MSS | Midwest Sociological Society |
| MSS | Mission Support System |
| MSS | Microsoft Sales Specialist |
| MSS | Mainzer Studienstufe |
| MSS | Maritime Satellite Service |
| MSS | Multispectral Scanner System |
| MSS | Market Stabilization Scheme (Reserve Bank of India) |
| MSS | Management System Standard |
| MSS | Master of Space Studies |
| MSS | Marinesco-Sjogren Syndrome |
| MSS | Member of the Same Sex |
| MSS | Message Switching System |
| MSS | M.S. Swaminathan (Indian agricultural scientist) |
| MSS | Master of Social Science |
| MSS | Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. (also seen as MSSVF) |
| MSS | Military Sensing Symposia |
| MSS | Mobile Soft Switch |
| MSS | Multiprotocol Switched Services (IBM) |
| MSS | Medical Support Services |
| MSS | Ministry of Social Services (replaced by Ministry of Human Resources and Social Development, Canada) |
| MSS | Marketing Support Services (New Richmond, OH; est. 1987) |
| MSS | Master of Social Service (degree) |
| MSS | Mobile Support Station |
| MsS | Magnetostrictive Sensor |
| MSS | Management Systems Solutions |
| MSS | Marshall-Smith Syndrome |
| MSS | Message Storage Server (Avaya) |
| MSS | Massena, NY, USA (Airport Code) |
| MSS | Mobile Service Structure |
| MSS | Master of Strategic Studies |
| MSS | Multi-State System |
| MSS | MAN Switching System (Seimens/Stromberg Carlson) |
| MSS | Midland Secondary School (Canada) |
| MSS | Minesweeper, Special (Device) |
| MSS | Minimum Service Standards |
| MSS | Market Segment Share |
| MSS | Maintenance Subsystem |
| MSS | Magnetic Sensing System |
| MSS | Mohammed Saeed al-Sahaf (former Iraqi Minister of Information) |
| MSS | Metropolitan Switching System |
| MSS | Market Survey System |
| MSS | Medical Student Society |
| MSS | Maximum Signal Strength |
| MSS | Monash Science Society (Monash University, Australia) |
| MSS | Mission Support Site (US military special forces) |
| MSS | Montfort Secondary School |
| MSS | Master-Slave Synchronization |
| MSS | Mutual Separation Scheme (Malaysia) |
| MSS | Mobility Services Suite (Symbol Technologies) |
| MSS | Modular Space Station |
| MSS | Mobile Support System |
| MSS | Manic Syndrome Scale |
| MSS | Maintenance, Start-Up, and Shutdown (Texas Commission on Environemental Quality) |
| MSS | Mechanical Systems Simulation |
| MSS | Memphis Soaring Society (aviation) |
| MSS | Measurement and Stimulus Subsystem |
| MSS | Missile System Supervisor |
| MSS | Mobile Switching Station |
| MSS | Mobile Servicing Station (space station) |
| MSS | Medical Service Specialist (USAF) |
| MSS | Microsoft Support Services |
| MSS | Marine Safety and Security |
| MSS | Management Statistics Subsystem |
| MSS | Marine Scout Sniper |
| MSS | Motion Sensing System |
| MSS | Military Supply Standard |
| MSS | Mine Search System |
| MSS | meteorological satellite subsystem (US DoD) |
| MSS | Millimeter Simulation System |
| MSS | Mechanically Separated Species |
| MSS | Missile Security Squadron |
| MSS | Merrimac State School (Gold Coast, Australia) |
| MSS | Mudgeeraba Special School (Gold Coast, Australia) |
| MSS | Maximum-Shear-Stress Theory (mechanical engineering) |
| MSS | Mission Systems Sector |
| MSS | Materials Science in Space |
| MSS | Maintenance Service Supplier |
| MSS | Meteorological Sounding Systems |
| MSS | Medium Sun Sensor |
| MSS | Maximum Soil Slope |
| MSS | Major Shore Spares |
| MSS | Mudgeeraba State School (Gold Coast, Australia) |
| MSS | Meterological Satellite System |
| MSS | Missile Surface-to-Surface |
| MSS | Modular Simulator System |
| MSS | Missionaries of the Blessed Sacrament (religious order) |
| MSS | maritime security surge (operations) |
| MSS | Manav Sthali School (New Delhi, India) |
| MSS | Miami State School (Gold Coast, Australia) |
| MSS | Modified Scram System |
| MSS | Market Share System (US Army recruiting) |
| MSS | Mission Scheduling System (NASA) |
| MSS | Middle Stage Switch |
| MSS | Mechanized Specification System |
| MSS | Main Shaft Speed |
| MSS | Military Supply Standards |
| MSS | Message Support Subsystem |
| MSS | Measure and Support Services (Sprint) |
| MSS | Mechanical and Structural Subsystems |
| MSS | Microprocessor System Status |
| MSS | Mormon Scripture Studies |
| MSS | Marine Salt Solution |
| MSS | McKeesport Symphony Society (McKeesport, Pennsylvania) |
| MSS | Matrix Switch System |
| MSS | Moored/Mobile Surveillance System |
| MSS | Muscle Signs and Symptoms |
| MSS | Multimedia Synchronization Server (Empirix) |
| MSS | Mississippi Space Service |
| MSS | Materiel Support System |
| MSS | Manufacturing Services Sector |
| MSS | Microprocessor Solutions Sector (various organizations) |
| MSS | Market Street Solutions (Chattanooga, TN) |
| MSS | Medical Surgical Supply |
| MSS | Management Software System |
| MSS | Metrocrest Social Services (Farmers Branch, TX) |
| MSS | Main Street Station |
| MSS | Miracle Software Systems (various locations) |
| MSS | Member Satisfaction Survey (various organizations) |
| MSS | Morehouse School of Medicine (est. 1975; Atlanta, GA) |
| MSS | Midlands Security Systems (UK) |
| MSS | Maxim Staffing Solutions (various locations) |
| MSS | Middle School South (various locations) |
| MSS | Municipal Support Services (various locations) |
| MSS | Medical Staff Services (various organizations) |
| MSS | Microsoft Search Server (software) |
| MSS | Multiple Steady State |