MMO

MMO may refer to:

Organizations

• Marine Management Organisation, a non-departmental public body of the UK Government
• Music Minus One, a music industry company

Science, technology, and biology

• Marine Mammal Observer, a professional in environmental consulting
• Methane monooxygenase, an enzyme
• Mixed metal oxide, a type of electrode
• Matyas-Meyer-Oseas (cryptography), a construction to build a hash function from a block cipher
• Mach Maximum Operating (M_MO), a speed limit shown on a machmeter
• Mercury Magnetospheric Orbiter, a key component of the ESA-led Mercury mapper BepiColombo
• Mini-Mag Orion, a proposed type of spacecraft propulsion

Other uses

• Massively Multiplayer Online, a multiplayer video game which is capable of supporting hundreds or thousands of players simultaneously
• Means, motive, and opportunity, three aspects of a crime (U.S.)
• Melton Mowbray railway station, National Rail station code MMO (England)
• Minimum Municipal Obligation, minimum contribution to a pension plan