| M&MOC | Maestro and Montego Owners Club 
| Others |
| MMOC | Malta Mini Owners Club
| Others |
| MMOC | Mary Mother of the Church (St. Louis, MO)
| Others |
| MMOC | Mazda Miata Owners Club
| Others |
| MMOC | Meanest Man on Campus (charity competition)
| Others |
| MMOC | Medical Marijuana of Orange County (Laguna Beach, CA)
| Others |
| MMOC | Mere Matter Of Code
| Others |
| MMOC | Michigan Metabolomics and Obesity Center (University of Michigan; Ann Arbor, MI)
| Others |
| MMOC | Midwives Model of Care (Citizens for Midwifery)
| Others |
| MMOC | Mini Marcos Owners Club
| Others |
| MMOC | Mini Marcos Owners Club (automobile club; UK)
| Others |
| MMOC | Mini Moke Owners Club
| Others |
| MMOC | Minicomputer Maintenance Operations Center
| Others |
| MMOC | Missile Maintenance Operations Center
| Others |
| MMOC | Mobile Miniature Operational Control Center
| Others |
| MMOC | Morris Marina Owners Club
| Others |
| MMOC | Morris Minor Owners Club
| Others |