| Abbreviation | Definition |
|---|---|
| MAGE | Mage Adventure Game Engine |
| MAI | Martial Arts Institute |
| MAIC | Minnesota Intercollegiate Athletic Conference |
| MANUFC | Manchester United Football Club |
| MAP | Most Active Player |
| MAR | Atos MARkham Pan Am / Parapan Am Centre |
| MARS | Muffin Andrew Rugby Start |
| MAS | Muungano All Stars |
| MASM | Mike Aaron Signature Model |
| MASN | Mid-Atlantic Sports Network |
| MASS | Muscle And Sports Science |
| MASS | Muscle Athletic Sports Society |
| MAWA | Middle Atlantic Wrestling Assosciation |
| MAWC | Middleton Area Wrestling Club |
| MAYC | Mid Atlantic Youth Conference |
| MB | Mechanical Bull |
| MB | Mid Bounce |
| MBA | Milford Basketball Association |
| MBA | Mississauga Baseball Association |
| MBA | Mobile Body Awareness |