| Bruxelles Linux User Group | Brussels-Capital |
| Bsit | |
| Bucoweb | Luxembourg |
| Bugtracker | |
| Build More | |
| BuildSoft | |
| Business Angels Europe a.s.b.l. | |
| Business Angels Region Stuttgart e.V. | |
| BuyIn | |
| BWS Brussels | |
| Byteflies | |
| C&C Computers & Communications | East Flanders |
| C-MAC Holding N.V. | East Flanders |
| C-Smart | |
| C.A. Dire | Walloon Brabant |
| Cactus, LLC | |
| Caiman CVBA | East Flanders |
| Canon Belgium N.V./S.A. | Flemish Brabant |
| Canon Business Center Brussels | Flemish Brabant |
| Capdirect | Hainaut |
| Capflow | Hainaut |
| Capricorn Partners | |
| Carflow | |
| Carta+ | |
| Cartel Agency | |
| Cartronics | Walloon Brabant |
| CAS B.V.B.A. | Limburg |
| Cashplannr | |
| Cassiopea A.S.B.L. | Brussels-Capital |
| Cats Communication | |
| Cats&Dogs | Limburg |
| CBM Informatique | |
| CDY | Hainaut |
| CEBEDEAU | |
| CEBEO | West Flanders |
| Cegeka | Limburg |
| Cegid Belgique | |
| Cellaion | |
| Cellistic | |
| Celyad Oncology | |
| Center for Drug Design and Discovery | |
| Centexbel | |
| CentOS | Flemish Brabant |
| CentralApp S.A. | |
| Centre Spatial de Liège | |
| Cerba Research | |
| CERM | West Flanders |
| CERT-EU | Brussels-Capital |
| CETIC A.S.B.L. | Hainaut |
| Champs-Libres | |