| Master Chips | East Flanders |
| Material S.A. | Brussels-Capital |
| Materialise N.V. | |
| Mathie Consulting | Liège |
| Mattias Geniar | |
| MCH Services | Brussels-Capital |
| MCProlog | Walloon Brabant |
| MDSoft S.P.R.L. | Namur |
| MeaWeb | Hainaut |
| MECOMS | |
| MedCalc | East Flanders |
| Media*A S.P.R.L. | Brussels-Capital |
| Media-Effect | East Flanders |
| Medialux | Luxembourg |
| Mediasoft B.V.B.A. | Limburg |
| MeDirect | |
| Medispring S.C.R.L. | |
| MedTech Flanders | |
| Mega-Tech Informatique S.P.R.L. | |
| Megabyte Applications | Walloon Brabant |
| Melexis | West Flanders |
| Meltem | Flemish Brabant |
| Mendoweb | Brussels-Capital |
| Metanous | |
| Metastore | Antwerp |
| MHConsultants S.R.L. | Hainaut |
| Microbus A.S.B.L. | Liège |
| Micromega Dynamics S.A. | |
| Microsoft Belgium | Flemish Brabant |
| Microtron | Antwerp |
| miDiagnostics | |
| Mijnwebsitebouwen.be | |
| Milky Web | Flemish Brabant |
| Mind OSS N.V. | Flemish Brabant |
| MindBytes | |
| Mintt | |
| Minze Health | |
| Miracor Medical S.A. | |
| Miredot | |
| Mission Systole | |
| Mission to Mars | |
| Mister Genius S.A. | Brussels-Capital |
| MIT-S Service Informatique | Walloon Brabant |
| Mixity Prompt IT Services | Walloon Brabant |
| MMi Solution S.R.L. | |
| Mms-Solutions | |
| Mobiel 21 | |
| Mobietrain | |
| MobileXpense | Brussels-Capital |
| MobilityPlus | |