| Navn | Postnummer | By |
|---|---|---|
| C.C.JENSEN A/S | 5700 | Svendborg |
| C.K. Environment A/S | 3500 | Værløse |
| C.K. Produktion | 7190 | Billund |
| Carl Stahl A/S | 7000 | Fredericia |
| Carlo Gavazzi Handel A/S | 8370 | Hadsten |
| Carsten Holm A/S | 5750 | Ringe |
| Castolin Scandinavia AB | 422 04 | Hisings Backa |
| CB Svendsen A/S | 3500 | Værløse |
| Celltech A/S | 3500 | Værløse |
| Centrum Pæle A/S | 7100 | Vejle |
| CERTEX Danmark A/S | 6500 | Vojens |
| Charles Christensen A/S | 2730 | Herlev |
| Cheminor A/S | 8543 | Hornslet |
| ComSystem A/S | 3490 | Kvistgård |
| Condair A/S | 8680 | Ry |
| Coreline A/S | 7000 | Fredericia |
| Coromatic A/S | 4000 | Roskilde |