| CMV Informatics | Côte-d'Or |
| CMV médiforce | |
| CNAM Auvergne - Rhône-Alpes | |
| CNDT | Seine-Maritime |
| CNM International | Bouches-du-Rhône |
| CNRS - IMS - Laboratoire de l'Intégration du Matériau au Système | |
| CO-F4 S.A.S. | Métropole de Lyon |
| Co-Libris | Vaucluse |
| Coactis | Bas-Rhin |
| Coaptis | Paris |
| Coave Therapeutics | |
| Coaxis | Lot-et-Garonne |
| Coaxis Informatique | Lot-et-Garonne |
| COBER | |
| Cobham Aerospace Communications | |
| Cockpit ITSM S.A.S. | |
| Coclico | Nord |
| Cocoom | |
| Code for France | |
| Code Lutin | Loire-Atlantique |
| Code-Garage | |
| code.store | |
| CodeDecode.net | Paris |
| Codeodis | Essonne |
| Codepi | |
| CodeS-SourceS | Paris |
| Codeur S.A.R.L. | Loire |
| Codi one | |
| Codiceo | |
| CodinGame | Hérault |
| Codingo | Hauts-de-Seine |
| Codix S.A. | Alpes-Maritimes |
| Codra | Essonne |
| Codris | Bas-Rhin |
| Coeur du Web | |
| Cofiem | Ain |
| Cofinoga | |
| CoFiSoft | Indre |
| Cogelec | Vendée |
| Cogeser S.A. | Haute-Garonne |
| Cogis Networks | Val-de-Marne |
| Cogistem | Paris |
| Cogitel Forum | Paris |
| COGITIS | |
| Cogivea | Charente-Maritime |
| CogNeed AI | |
| Cognix Systems | Ille-et-Vilaine |
| Coheris | Hauts-de-Seine |
| Coif2000 | Haute-Marne |
| ColibriTD | |