MMO
MMO may refer to:
Entertainment
- Massively multiplayer online game, a video game that can be played by many people simultaneously
- Music Minus One, a record company in Westchester, New York
Science and technology
- Methane monooxygenase, an enzyme
- Maximum operating Mach number
- Mercury Magnetospheric Orbiter, a component of the Mercury mapper BepiColombo
- Mini-Mag Orion, a proposed type of spacecraft propulsion
- Mixed metal oxide, a class of materials often used in electrodes
Other
- Means, motive, and opportunity, the "indicators of suspicion"
- Minimum municipal obligation, minimum contribution to a pension plan
- Maio Airport, in Cape Verde, IATA code
- Melton Mowbray railway station, England (National Rail station code MMO)
- Marine Management Organisation, UK government body
- Marine mammal observer, a professional in environmental consulting