| MMSA | Mad Madison Sports Authority 
| Others |
| MMSA | Mahindra and Mahindra South Africa
| Others |
| MMSA | Mail me some art
| Others |
| MMSA | Maine Mathematics Science Alliance
| Others |
| MMSA | Malta Medical Students Association
| Others |
| MMSA | Malta Medical Students' Association
| Others |
| MMSA | Mansfield Middle School Association
| Others |
| MMSA | Marshall Math Science Academy
| Others |
| MMSA | Master of Midwifery of the Society of Apothecaries
| Others |
| MMSA | Materials and Methods Standards Association
| Others |
| MMSA | Maternity of Mary Saint Andrew
| Others |
| MMSA | Media Marketing Sponsorships Artist
| Others |
| MMSA | Medical Mycological Society of the Americas
| Others |
| MMSA | Mercantile Marine Service Association
| Others |
| MMSA | Methanol Market Services Asia
| Others |
| MMSA | Methodology Measurement and Statistical Analysis
| Others |
| MMSA | Metro Midrange Systems Association
| Others |
| MMSA | Metropolitan Micropolitan Statistical Areas
| Others |
| MMSA | Michigan Math and Science Academy
| Others |
| MMSA | Midwest Military Simulation Association
| Others |
| MMSA | Midwest Mini Sprint Association
| Others |
| MMSA | Midwest Mini Srint Association
| Others |
| MMSA | Milwaukee Math and Science Academy
| Others |
| MMSA | Mining and Metallurgical Society of America
| Others |
| MMSA | Minnesota Math and Science Academy
| Others |
| MMSA | Minnesota Middle School Association
| Others |
| MMSA | Minnesota Mine Safety Association
| Others |
| MMSA | Mitsubishi Motor Sales of America
| Others |
| MMSA | Mitsubishi Motors South Africa
| Others |
| MMSA | Money Management Share Account
| Others |
| MMSA | Money Market Savings Account
| Others |
| MMSA | Muhammadiyah Medical Students Activities
| Others |
| MMSA | Must Medical Sensual Association
| Others |