| Navn | By |
|---|---|
| C K Produktion A/S | Billund |
| CAD Kompagniet A/S | Herlev |
| Carl Stahl A/S | Fredericia |
| Carl Zeiss A/S | Birkerød |
| Carlo Gavazzi Handel A/S | Hadsten |
| Carsten Holm A/S | Ringe |
| CB Svendsen A/S | Værløse |
| CCM Electronic Engineering | Sønderborg |
| Celltech A/S | Værløse |
| Chemo Electric A/S | Smørum |
| ComSystem A/S | Kvistgård |
| Condair A/S | Ry |
| CORE-emt A/S | Aars |
| CORNATOR A/S | Viborg |
| Coromatic A/S | Roskilde |
| Cp Sourcing ApS | Roslev |
| Craneteam ApS | Låsby |
| Cre8tek Denmark ApS | Hjørring |