| Concileo | Paris |
| Conécom | Vienne |
| Conecs | |
| Conférence des grandes écoles | |
| ConFIG | Paris |
| Conformitee | |
| congreSoft | |
| CONIBI | |
| CONIX | Hauts-de-Seine |
| Connect Data | Essonne |
| Connect Lab | Gironde |
| Connecting Food | |
| Connectiv-IT | |
| Connector | Paris |
| Connex-it | Métropole de Lyon |
| Connexing | Loire-Atlantique |
| Connexing | |
| Connit | Haute-Garonne |
| Conseil Assistance Ingénierie Informatique | Moselle |
| Conseil Config | Paris |
| Conseil Info | |
| Conseil National du Numérique | Paris |
| Conseil supérieur de l'audiovisuel | Paris |
| Conseil.biz | Val-de-Marne |
| Consept | Loire-Atlantique |
| Consomac | Métropole de Lyon |
| Consommables.com | Indre-et-Loire |
| Constellation | Pyrénées-Orientales |
| Constellation | |
| Constellation | |
| Constructys | |
| Consulog | Var |
| Consultants Informatique Associés | Paris |
| Contact Azur | Alpes-Maritimes |
| ContentArmor | |
| ContentSide | Paris |
| ContentSquare | Paris |
| Continuity S.A.S. | |
| Conty | Sarthe |
| Conv2pdf | Gironde |
| Convers Télémarketing | Alpes-Maritimes |
| Convertigo S.A. | |
| ConvertPDFtoWord.net | Métropole de Lyon |
| ConviSAV | Morbihan |
| CONVIWEB | Bouches-du-Rhône |
| Copem S.A.S. | Val-de-Marne |
| Copiafax | Côte-d'Or |
| Copieur System | Isère |
| Copilot Partners | Paris |
| Copysud | Haute-Garonne |