MSS (disambiguation)
- IBM 3850
- List of equipment of the United States Army
- List of mine warfare vessels of the United States Navy
- MSS
- Managed security service
- Manassas (Amtrak station)
- Manuscript
- Marine Corps University
- Mario Super Sluggers
- Marshall–Smith syndrome
- Marsiling Secondary School
- Marymount Secondary School
- Massena International Airport
- Master of Social Science
- Maximum segment size
- Meridian Secondary School
- Merseyside Skeptics Society
- Meskwaki Settlement School
- Microsatellite instability
- Microsoft Search Server
- Midland Secondary School
- Miles Sound System
- Ministry for State Security (disambiguation)
- Mobile Servicing System
- Mobile switching centre server
- Mobile-satellite service
- Monkton Combe School
- Montfort Secondary School
- Montserrat Secondary School
- Moses Gate railway station
- Movable scaffolding system
- Multispectral Scanner
- Music Source Separation
- Pentlandite
- Piping and plumbing fitting
- Shetland dialect
- The Mother's Service Society