| CryptoSimple S.A.S. | |
| CryptPad | Paris |
| Cryptr | |
| CS Informatique | Mayenne |
| CS Programme | Haute-Savoie |
| Cs2i Bourgogne | Nièvre |
| CsetID | Haute-Savoie |
| CTO Partners Group S.A.S. | |
| CTR Télécom | Isère |
| Cubde | Loire-Atlantique |
| Cube S.A.R.L. | Vendée |
| Cube43 | |
| Cubedesigners | Paris |
| Cubinfo | Haute-Saône |
| Cubyn | Paris |
| Cuers-Informatique | Gironde |
| Curadigm | |
| Curecall | |
| Curseur | |
| CVasThera | Tarn |
| CVFM Webmarketing | Paris |
| CVMH Solutions | Eure-et-Loir |
| CX Informatique | |
| CXR | Eure-et-Loir |
| CybelAngel | |
| Cyber07.com | Ardèche |
| Cyberbrain | Ille-et-Vilaine |
| CyberCité | Métropole de Lyon |
| CyberComm | Alpes-Maritimes |
| Cyberiance | Doubs |
| Cyberjobs | |
| Cybermalveillance.gouv.fr | Paris |
| Cybernétix | Bouches-du-Rhône |
| Cybernettic | Creuse |
| Cyberprotect | Métropole de Lyon |
| Cyberté Création S.A.R.L. | Drôme |
| CyberVadis S.A.S. | |
| Cyberwatch | |
| Cyceo Informatique | Hauts-de-Seine |
| Cycle | |
| Cyllene S.A.S. | Paris |
| Cymax Studios | Tarn-et-Garonne |
| Cyres | Paris |
| Cyril Vincent Conseil | Isère |
| CYTOO S.A. | |
| CYWYC | |
| D&A Pharma | |
| D-AIM | Hauts-de-Seine |
| D-EDGE | Paris |
| D-Fuzion | Gironde |