| Mars Rouge | Haut-Rhin |
| MarseilleWeb | Bouches-du-Rhône |
| Marwael | Val-d'Oise |
| Marxer Informatique | Bas-Rhin |
| Mas Informatique | Bas-Rhin |
| MASA Group S.A. | Paris |
| Mash Up France | |
| Massalia Therapeutics | |
| Masse Analytics | |
| Master 2 PiSE | Paris |
| Mata Capital | |
| Matera S.A.S. | Paris |
| Matera S.A.S. | |
| Material UI S.A.S. | |
| Matériel-Informatique-Occasion.com | Yvelines |
| Materiel.net | Loire-Atlantique |
| Mathdoc | |
| Matheo Software | Bouches-du-Rhône |
| Maths à Harry | Paris |
| Maths-Rometus | Paris |
| Maths.net | Paris |
| MathsLand | Paris |
| Matière 1ère | |
| Matière Grise Consulting | Paris |
| Matra Électronique | Oise |
| Matters S.A.S. | |
| Mauna Kea Technologies | Paris |
| Maxinfoweb S.A.R.L. | Oise |
| MaxWeb | Marne |
| MAYD'AI Assistance Informatique | Haute-Garonne |
| Mayday Net | Val-d'Oise |
| Maysonnave Informatique | Pyrénées-Atlantiques |
| Maze | |
| Mazedia | Loire-Atlantique |
| Mazet Web Communication | Bouches-du-Rhône |
| Mazuel PC | Puy-de-Dôme |
| MB Electronique | Yvelines |
| MB Therapeutics | |
| MB2i | Haute-Savoie |
| MBA ESG | |
| MC&C | Loire |
| MCA Technology | |
| MCA-NET | Bouches-du-Rhône |
| MCI Monté Câblé Industriel | Puy-de-Dôme |
| MCI32 | Gers |
| MCS Group | Alpes-Maritimes |
| MD Start | |
| MD6 | |
| MDBat | |
| MDP Qualité S.A.R.L. | Haute-Garonne |