| Acronym | Definition |
|---|
| MTSA | Multiple Time Series Analysis (marketing) |
| MTSA | Marine Transportation Security Act (Canada) |
| MTSA | Middle Tennessee School of Anesthesia (Madison, TN) |
| MTSA | Military Training Specific Allotment |
| MTSA | Minnesota Transport Services Association |
| MTSA | McCandless Township Sanitary Authority (Pennsylvania) |
| MTSA | Master Teachers by Satellite for Afghanistan (educational program) |
| MTSA | Master Transit Services Agreement (Fluxys; Belgium) |
| MTSA | Medical Tourism Association of South Africa |
| MTSA | Seaman Apprentice, Missile Technician Striker (Naval rating) |
| MTSA | Multi Technical Services Arnhem (Arnhem, The Netherlands) |