MMX may refer to:

• 2010, in Roman numerals

• MMX (instruction set), a single-instruction, multiple-data instruction set designed by Intel
• MMX Mineração, a Brazilian mining company
• Martian Moons eXploration, a Japanese mission to retrieve samples from Mars' moon Phobos
• Michelson–Morley experiment, an 1887 physics experiment

• MMX Open Art Venue, in Berlin, Germany
• Malmö Airport, Sweden (IATA code)

• "MMX (The Social Song)", a 2010 song by Enigma
• MMX (Twelfth Night album), 2010
• Napalm (album), original working title MMX, a 2012 album by Xzibit
• MMX, a 2012 album by Procol Harum
• MMX, a 2010 album by War from a Harlots Mouth
• Marble Machine X, a musical instrument designed by Swedish band Wintergatan

• Mega Man X, a series of video games, and its main character
• Might & Magic X: Legacy, a 2014 role-playing video game