MMU may refer to:

Science and technology

• Memory management unit, a computer component
• Manned Maneuvering Unit, a NASA spacesuit rocket pack
• Milli mass unit, an unofficial unit of mass
• Minimum Mapping Unit, a spatial measure used in remote sensing and cartography

Education

• Manchester Metropolitan University, in England
• Marymount University, in Arlington, Virginia
• Mount Mansfield Union High School, in Jericho, Vermont
• Mount Meru University, in Tanzania
• Mountains of the Moon University, in Fort Portal, Uganda
• Multimedia University, in Malaysia
• Myanmar Maritime University

Other

• Mobile Meteorological Unit, a deployable weather forecasting support unit of the British Armed Forces
• Monomethylurea, one of the ureas, used in synthetic medications
• Morristown Municipal Airport (IATA code MMU), in New Jersey
• Mega Man Universe, a game by Capcom
• Milli Muharip Uçak, a Turkish fighter aircraft in development