| M | Magnetic: MET-Reporting Point (RFC) |
| m/M | Meter(s) |
| M/A | Missed Approach |
| MAA | Maximum Authorised Altitude |
| MAG | Magnetic |
| MAINT | Maintenance |
| MALS | Medium Intensity Approach Lighting System |
| MALSF | Medium intensity Approach Light System with Sequenced Flashing Lights |
| MALSR
| Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights |
| MAP | Aeronautical Maps and Charts |
| MAP | Missed Approach Point |
| MAPt | Missed Approach Point |
| MAR | March |
| MATZ | Military Aerodrome Traffic Zone |
| MAX | Maximum |
| Max | Maximum (Altitude restrictions on ARR/DEP/APP charts |
| MAY | May |
| MB | Millibars |
| MBO | Manual Basic Operations (IB) |
| MBOH | Minimum Break Off Height |
| MBZ | Mandatory Broadcast Zone |
| MCA | Minimum Crossing Altitude |
| MCA | Minimum Cruising Altitude |
| MCA | Military Controlled Airspace |
| MCL | Minimum Cruising Level |
| MDA | Minimum Descent Altitude |
| MDH | Minimum Descent Height |
| MDT | Mountain Daylight Time |
| MEA | Minimum Safe En route Altitude |
| MEHT | Minimum eye height over Threshold |
| MEML | Memorial |
| MER | True Height Above Mean Sea Level |
| MET | Meteorology, meteorological |
| MF | Medium Frequency (300 - 3000 kHz) |
| MGA | Minimum Safe Grid Altitude |
| MH | Magnetic heading |
| MHA | Minimum Holding Altitude |
| MHz | Megahertz |
| MI | Medium Intensity (lights) |
| MIAL / MIALS | Medium Intensity Approach Light System |
| MIALR | Medium Intensity Approach Lights with Runway Alignment Indicator Lights |
| MID/Asia | Middle East/Asia (ICAO Region) |
| MIL | Military |
| MIM | Minimum |
| MIN | Minute(s) (on ARR/DEP/APP charts) |
| Min | Minute(s) |
| MIRCLL | Medium Intensity Runway Centre Line Lights |
| MIRL | Medium intensity Runway Edge Lights |
| MISC | Miscellaneous |
| MKGS | Marking |
| MKR | Marker Radio Beacon |
| MLS | Microwave Landing System |
| MLW | Maximum Certificated Landing Weight |
| MM | Middle Marker |
| MNM | Minimum |
| Mnm | Minimum (Altitude restrictions on ARR/DEP/APP charts) |
| MNPS | Minimum Navigational Performance Specifications |
| MNTN | Maintain/maintaining |
| MOC | Minimum Obstacle Clearance |
| MOA | Military Operation Area |
| MOCA | Minimum Obstruction Clearance Altitude |
| MON | Monday |
| MORA | Minimum Off-Route Altitude |
| MOT | Ministry of Transport (Canada) |
| Mph / MPH | Statute Miles per Hour |
| mps / MPS | Meters per Second |
| MPW | Maximum Permitted Weight |
| MRA | Minimum Reception Altitude |
| MRK | Marking |
| MRP | ATS/MET reporting point |
| MS | Minus |
| MSA | Minimum Sector Altitude |
| MSG | Message |
| MSL | Mean Sea Level or vertical distance without temperature correction |
| MST | Mountain Standard Time |
| MT | Magnetic Track |
| MT | Mount |
| mt | metric ton (2204.6 lbs) |
| MTA | Military Training Area |
| MTAF | Mandatory Traffic Advisory Frequency |
| MTCA | Minimum Terrain Clearance Altitude |
| MTMA | Military Terminal Control Area |
| MTOW | Maximum Take-off Weight |
| MTWA | Maximum Total Weight Authorised |
| MUN | Municipal |
| MUTA | Military Upper Traffic Control Area |
| MVA | Minimum Vectoring Altitude |
| MVFR | Marginal VFR |
