| Chapps N.V. | |
| ChatGPT, Generative AI and GPT-3 Apps and use cases | |
| Cheops | Antwerp |
| Cheqroom | |
| Chili | East Flanders |
| CHILI publish N.V. | |
| Christiaens | West Flanders |
| CISA | |
| Cissoid | Walloon Brabant |
| CitizenLab | Brussels-Capital |
| Citymesh Wireless Networks | West Flanders |
| ClearMedia N.V. | |
| Clef2web | |
| Clevercast | Antwerp |
| CleverPC | East Flanders |
| Clicktouch N.V. | East Flanders |
| Clinitude | |
| Cloud Innovation | |
| Cloudalize | East Flanders |
| Cloudar N.V. | |
| Cluster TIC Infopole | Namur |
| CMR-JET | Flemish Brabant |
| CO-carré S.P.R.L. | |
| Cobra Technology B.V.B.A. | |
| CodiCo.io | |
| Coemans.com | Limburg |
| Cohabs | |
| Colibris | Antwerp |
| Collaboration Betters The World | |
| College of Europe | West Flanders |
| ColmSoft | Antwerp |
| Colruyt Group | |
| Combel N.V. | East Flanders |
| Comeplan | Brussels-Capital |
| Comité Européen de Normalisation Electrotechnique | Brussels-Capital |
| Companion Energy | |
| Comperex Belgique S.A. | Flemish Brabant |
| Complidata | |
| Complix | |
| Comptoir Belge de Télécommunications | Brussels-Capital |
| Compubel | |
| Compucenter | West Flanders |
| Compumsa.eu | Walloon Brabant |
| Computaid SPRL | Walloon Brabant |
| Computer Checkpoint | |
| Computer Futures | Brussels-Capital |
| Computercentrum | East Flanders |
| Computerland | |
| Comsa B.V.B.A. | West Flanders |
| Comsof | East Flanders |