MSR may refer to:

Science and technology

* MSR1, Macrophage scavenger receptor, a receptor found in macrophages * Magnetic stripe reader, a device used to read magnetic stripe cards such as credit cards * M–sigma relation, in astrophysics * Mars sample return mission, a spaceflight mission to return rock and dust samples collected on Mars * Mirror self-recognition, in animals through the mirror test * Molten salt reactor, an advanced nuclear reactor design

Computing

* Machine state register, a register used in PowerPC architectures * Model-specific register, a feature in x86 processors * Microsoft Reserved Partition, a space-management partition on a computer storage device * Mining software repositories, a field that analyzes the rich data available in software repositories

Entertainment

* MSR Studios, a New York recording studio * The Most Serene Republic, a Canadian indie rock band * ''Metropolis Street Racer'', a Dreamcast racing game * Mid-season replacement, a television series that premieres in the second half of a traditional season *''Metroid: Samus Returns'', a video game * Mulder Scully Romance, the relationship of the main characters of the television series ''The X-Files''

Organizations and companies

* Market Street Railway (nonprofit), a historic preservation organization in San Francisco, California, U.S. * Microsoft Research, the research division of Microsoft * Mountain Safety Research, a US company specializing in outdoor equipment * Mouvement social révolutionnaire, the French fascist party Revolutionary Social Movement * Movimiento Social Republicano, the Republican Social Movement political party in Spain * MSR - The Israel Center for Medical Simulation, Israeli institute for Simulation-Based Medical Education

Places

* Most Serene Republic, a title in the name of various countries * Montserrat (ISO 3166-1 code)

Transportation

* EgyptAir (ICAO designator), an Egyptian airline * Main supply route, a military operations supply route * Market Street Railway (transit operator), a defunct company in California, U.S. * Maserati, a luxury sports car company * Michigan Shore Railroad, US * Muar State Railway, a defunct railway formerly operating in the Johor Sultanate, British Malaya * Mumbai Suburban Railway, India * Muş Airport (IATA airport code), Turkey

Weapons

* Modern sporting rifle or AR-15 style rifle * Modular Sniper Rifle, a sniper rifle produced by Remington Arms * Magnum Sniper Rifle or Accuracy International Arctic Warfare, a bolt-action sniper rifle

Other uses

* Market Stability Reserve, a part of the European Union Emission Trading Scheme * Milan–San Remo, an annual bicycle race * Mortgage servicing rights, the rights to collect mortgage payments from a borrower for the benefit of the lender * Meyer Shank Racing, an American auto racing team {{disambiguation