| CIT Formation | Vaucluse |
| Cité de l'Espace | Haute-Garonne |
| Cité des énergies | |
| Cité des télécoms | Côtes-d'Armor |
| Cité Numérique | Gironde |
| Cite-sciences | Paris |
| Citech | |
| Citegestion | Paris |
| Citizen Capital | |
| CitizenCan | |
| Citron | |
| CityScan | |
| Cityway | Bouches-du-Rhône |
| Civitime | |
| Civocracy S.A.S. | |
| CKR Solutions Open Source | Alpes-Maritimes |
| Clair de Vue | |
| Clait et Net | Paris |
| Clapy | |
| Clara | Calvados |
| Clara Vision | Essonne |
| Claranet S.A.S. | Paris |
| Claranova | Hauts-de-Seine |
| Clariance S.A.S. | |
| ClariLog France | Aisne |
| Clariteam S.A.S. | Hauts-de-Seine |
| ClassExpert | Alpes-Maritimes |
| Clean Cells | |
| Cleaning Informatique | Métropole de Lyon |
| Clear Channel | |
| Clear Fashion | |
| Clearsy | Bouches-du-Rhône |
| CLEIA S.A.S. | Côte-d'Or |
| Clémence Consulting | |
| Cleona | Paris |
| Clerc & Net | Drôme |
| Clermont Auvergne Innovation | |
| Clermont School of Business | |
| Clesia gestion | |
| Clever Age | Paris |
| Clever Cloud | |
| Clever Technologies | Seine-et-Marne |
| CleverConnect | |
| CleverMate | |
| CleverSMS | Seine-et-Marne |
| Clevexel Pharma S.A. | |
| Cleyrop | |
| Clic-event.com | Ille-et-Vilaine |
| Clic15 | Cantal |
| ClicData | |