| Contentoo | North Holland |
| ContentToday.nl | Utrecht |
| Control Space B.V. | |
| Controllab Products | Overijssel |
| ConvenienceWare | North Holland |
| Convenient Software Solutions | South Holland |
| Conversation Design Institute B.V. | |
| Conversive | Flevoland |
| Convious | North Holland |
| CooBit | |
| CookieFirst | North Holland |
| Coolblue N.V. | |
| CoolGames | North Holland |
| CoolProofs | South Holland |
| Coopmans Excelspecialist | North Brabant |
| Copaco Netherlands B.V. | North Brabant |
| Copernicus Interchange Technology | North Holland |
| Copier service | Groningen |
| Coppa | |
| CoreDux Netherlands B.V. | |
| Corened | Gelderland |
| Cornellsys ICT | North Brabant |
| Corpeq Green Protein Fund | |
| Corporify B.V. | |
| Corporise | |
| Correcthosting | Utrecht |
| Corsano Health | |
| Cortalix B.V. | |
| CorTexter Technologies B.V. | |
| COSA B.V. | Utrecht |
| Cosine Measurement Systems | |
| CoSo | |
| Countr | |
| Coval B.V. | Utrecht |
| CoVince | |
| Cow Hills Retail | Utrecht |
| CQM - Specialists in Quantitative Modelling | North Brabant |
| Crayonic | North Brabant |
| CreAim B.V. | North Holland |
| Creatilt | North Holland |
| Creation Online Marketing | South Holland |
| CreativAI | |
| Creative ICT B.V. | Overijssel |
| Creative PC Training | North Holland |
| CreativeWeb B.V. | |
| Crebos | |
| Creja Ontwerpen B.V. | South Holland |
| Crisp B.V. | North Holland |
| Cristal Therapeutics | |
| Critical Bit | |