| Acronym | Definition |
|---|
| MMJ | Medical Marijuana |
| MMJ | Multimedia Journalist |
| MMJ | My Morning Jacket (band) |
| MMJ | Matsumoto Airport (Japan) |
| MMJ | Malta Medical Journal |
| MMJ | Musicmatch Jukebox |
| MMJ | Malawi Medical Journal (quarterly publication) |
| MMJ | Mainichi Medical Journal (Japan) |
| MMJ | Mymensingh Medical Journal (Bangladesh) |
| MMJ | Moscow Mathematical Journal (Independent University of Moscow; Russia) |
| MMJ | Modified Modular Jack |
| MMJ | Mutuelle du Ministère de la Justice (French: Mutual Ministry of Justice) |
| MMJ | Michigan Mathematical Journal (Department of Mathematics; University of Michigan) |
| MMJ | Mitchell, Maxwell & Jackson, Inc. (real estate appraisals; New York, NY) |