MGS
- M1128 mobile gun system
- MG (disambiguation)
- MGS (TV station)
- Magnesium sulfide
- Maidstone Grammar School
- Manchester Grammar School
- Mars Global Surveyor
- Mayo Clinic Graduate School of Biomedical Sciences
- Melbourne Grammar School
- Meldorfer Gelehrtenschule
- Metal Gear Solid
- Metal Gear Solid (1998 video game)
- Methodist Girls' School (disambiguation)
- Microsoft Game Studios
- Middleton Grange School
- Modelling of General Systems