MB stands as an abbreviation for:
- Manitoba, a Canadian province
- Turks and Caicos Islands by ICAO code
- Mercedes-Benz, a German automobile brand
- MB Spiele, US-American game and toy manufacturer, see Milton Bradley Company
- MB Miðvágur, a Faroese football club from Miðvágur
- MNG Airlines, Turkish cargo airline (IATA code)
- Methyl bromide, a chemical compound
- Motor Buggy Manufacturing Company, former US automobile manufacturer
Culture:
- Maurizio Bianchi, as a pen name in his earlier publications.
- Missal of the Catholic Church
- Moritzbastei, part of the former city fortifications of Leipzig, today a cultural centre
- Musica Britannica, a music-historical edition of works
Politics and Law:
- Dunning order, see Dunning procedure
- Marburger Bund, German professional association and trade union for medical professionals
- Marching orders
- Marxist Papers
- Milton Bryan, cover name for a British department in World War II responsible for psychological warfare.
- Ministerial Representative
- Membership fee in the law of associations
- Muslim Brotherhood, an Islamist movement
Technology:
- Mainboard or motherboard, the motherboard
- Mechanical Engineering
- Megabyte (decimal prefix), abbreviation for 106 bytes = 1,000,000 bytes; see Byte#Prefixes
- Molecular Beam
- Moselbahn, a former railway company
- Samoa Airlines, ICAO code of this former carrier
Numismatics:
- Mintmaster's marks of the tipper mint in Großenhain 1621 and mintmarks of the tipper mint in Merseburg 1621 to 1622
MB as distinguishing sign on vehicle registration plates
- Albania: Police (for Ministria Brendshme, Ministry of the Interior, with blue inscription)
- Germany: County of Miesbach
- Great Britain: Manchester
- Italy: Monza e Brianza
- Netherlands: Motorcycles
- Slovakia: dealer's plate (white plate with red lettering: second group of letters)
- Slovenia: Maribor
- Czech Republic: Okres Mladá Boleslav (expiring)
- Turkey: Foreigners with residence permit
mb is for:
- Millibar, the thousandth part of the unit bar (unit) for pressure.
Mb is for:
- Megabase pairs (also Mbp), as an abbreviation for 1,000,000 base pairs in molecular biology.
- Megabit (decimal prefix), a less common abbreviation for 106 bits = 1 MBit or 1,000,000 bits; see bit.
- Morbus, the Latin word for disease
mB or mb stands for:
- Space wave magnitude scale, an earthquake scale