| Abbreviation | Definition |
|---|---|
| MTSI | Mendenhall Technical Services Inc |
| MTSI | Microwave Transmission Systems Inc |
| MTSI | Moseley Technical Services Inc |
| MTSL | MER Telemanagement Solutions Ltd |
| MTSO | Medical Transcription Service Organization |
| MTSS | Media Technology Support Services |
| MTTF | Morrow, Tompkins, Trueblood, Lefevre, L.L.C. |
| MTTF | Morrow, Tompkins, Trueblood, & Lefevre, L.L.C. |
| MTTG | Machine Tool Technology Group |
| MTTI | Molecular Targeting Technologies Inc |
| MTVC | Makkah Techno Valley Company |
| MTVFC2 | Montgomery Township Volunteer Fire Company #2 (Montgomery, New Jersey) |
| MTVL | Max Telecom Ventures Ltd |
| MTW | Models That Work |
| MTZ | Minski Traktorny Zavod |
| MUFB | Manchester United Food and Beverage Group |
| MUFG | Mitsubishi UFJ Financial Group |
| MUFJ | Mitsubishi UFJ Financial Group |
| MUFO | MUsikskolernes FOrlag |
| MUIA | Military Uniforms in America (Company of Military Historians) |