| Acronym | Definition |
|---|
| MCARS | Marion County Amateur Radio Society (Indianapolis, IN) |
| MCARS | Malaspina College Amateur Radio Society (Vancouver Island University; British Columbia, Canada) |
| MCARS | Marshall County Auxiliary Radio Service (Alabama) |
| MCARS | Marshall County Alabama Repeater System (amateur radio) |
| MCARS | Mc-130h Air Refueling System |
| MCARS | Monmouth County ARES (Amateur Radio Emergency Service), RACES (Radio Amateur Civil Emergency Service), Skywarn (amateur radio; New Jersey) |
| MCARS | Model Combat Air Refueling System |