MR, Mr, mr, or mR may refer to:
- Mr., an honorific title of men
Arts, entertainment, and media
- MR (Marina and Rainer) (1989), a 1994 one-act chamber opera by Nikolai Korndorf
- Magyar Rádió, a Hungarian radio station
- Mixed reality, the merging of real and virtual worlds
- Model Railroader, a US hobby magazine
- Meta Runner, an Australian web series.
Identification codes
- .mr, the country code top level domain (ccTLD) for Mauritania
- Air Mauritanie (IATA code)
- Marathi language (ISO 639-1 code "mr")
- Martinique, country code (World Meteorological Organization)
- Mauritania, country code (ISO 3166-1 Alpha-2, FIPS 10-4)
- Morocco, country code (Library of Congress MARC standards)
Science
- Magnetoresistance, change in electrical resistance due to a magnetic field
- Mendelian randomization, a way of using genetic information to estimate causal effects
- Mental retardation
- Mineralocorticoid receptor
- Mitral regurgitation of blood flow in the heart
Transportation
- M.R. (automobile), a microcar model built in 1945
- Midland Railway, a United Kingdom railway
- Nissan MR engine
- Rear mid-engine, rear-wheel-drive layout, an automotive layout
Other uses
- Chief Maqoma Regiment, an infantry regiment of the South African Army
- Mr. (artist) (born 1969), Japanese artist
- Mr. (band), a Hong Kong pop rock band
- Master of the Rolls, the President of the Court of Appeal of England and Wales, Civil Division, and Head of Civil Justice
- Menntaskólinn í Reykjavík, junior college in Iceland
- Mouvement Radical (Radical Movement), a French political party
- Mouvement Réformateur, a Belgian political party
See also
- Magnetic resonance (disambiguation)
- Mister (disambiguation)