MSR
- Arknights
- EgyptAir
- European Union Emission Trading Scheme
- ISO 3166-1
- MSR Studios
- MSR – The Israel Center for Medical Simulation
- MSR1
- Machine state register
- Magnetic stripe reader
- Magnum Sniper Rifle
- Main supply route
- March, Strathspey and Reel
- Market Street Railway (nonprofit)
- Market Street Railway (transit operator)
- Mars sample return
- Maserati
- Metropolis Street Racer
- Meyer Shank Racing
- Michigan Shore Railroad
- Microsoft Research
- Microsoft Reserved Partition
- Mid-season replacement
- Milan–San Remo
- Mining software repositories
- Mirror self-recognition
- Misamis Oriental
- Model-specific register
- Modern sporting rifle
- Modular Sniper Rifle
- Molten salt reactor
- Montserrat
- Mortgage servicing rights
- Most Serene Republic
- Mountain Safety Research
- Mouvement social révolutionnaire
- Movimiento Social Republicano
- Muar State Railway
- Mumbai Suburban Railway
- Muş Airport
- M–sigma relation
- The Most Serene Republic
- The X-Files