MB

MB, Mb, mB or mb may mean:
 Megabit (1,000,000 bits), preferred symbols Mb
 Megabyte (1,000,000 bytes), preferred symbol MB
 Mebibyte (220 = 1,048,576 bytes), preferred symbol MiB

MB may mean:
 Bachelor of Medicine, an academic degree (Latin Medicinae Baccleureus)
 MacBook, an Apple Computer
 Manitoba (Canadian Province/Territory Code)
 Maribor, a city in Slovenia
 Martinique: FIPS PUB 10-4 territory code
 Medal of Bravery (Canadian decoration post-nominal letters)
 Mercedes-Benz, a German brand of automobiles, buses, coaches and trucks
 Motherboard

Mb may mean:
 Myoglobin, a type of protein chain

mb may mean:
 Millibar, a unit of pressure. Sometimes written as mBar.