| Celus GmbH | |
| CEMA IT Systemhaus GmbH | North Rhine-Westphalia |
| Cemore GmbH | Lower Saxony |
| CENIT | Baden-Württemberg |
| Censhare | |
| Center for Digital Technology and Management | Bavaria |
| Center for Entrepreneurship der Heinrich-Heine-Universität Düsseldorf | North Rhine-Westphalia |
| Center for Integrated Quantum Science and Technology | Baden-Württemberg |
| Center for Optoelectronics and Photonics Paderborn | |
| CenterDevice GmbH | |
| Centerweb.de | Lower Saxony |
| Centigrade GmbH | Saarland |
| Central Media GmbH | Berlin |
| Centrifuge | Berlin |
| Centron GmbH | Bavaria |
| Ceous Solutions | |
| Cephei AG | Bavaria |
| CepNet | |
| CEPRES GmbH | |
| CeramOptec GmbH | North Rhine-Westphalia |
| Cerca Biotech | Berlin |
| Cere Network | |
| Ceritech AG | |
| Cerobear GmbH | |
| Certif-ID International GmbH | |
| Certivity GmbH | |
| Certmedica International GmbH | |
| CESOFT | North Rhine-Westphalia |
| CESYS Gesellschaft für angewandte Mikroelektronik mbH | Bavaria |
| CeTI - Centre for Tactile Internet with Human-in-the-Loop | Saxony |
| Ceyoniq Technology GmbH | North Rhine-Westphalia |
| CFgO GmbH | |
| Cfm Oskar Tropitzsch GmbH | |
| cFos Software GmbH | North Rhine-Westphalia |
| CFturbo GmbH | Saxony |
| CFX Berlin Software GmbH | Berlin |
| CG IT-Solutions GmbH | |
| CGM Systemhaus GmbH | |
| CGM Technology Services | Hesse |
| Cgnote GmbH | |
| CGRateS | |
| Chamaeleon AG | Rhineland-Palatinate |
| Channel Guru GmbH | |
| Channel Microelectronic GmbH | |
| Channel Pilot Solutions GmbH | |
| Chaos Computer Club Cologne e.V. | North Rhine-Westphalia |
| Chaos Computer Club e.V. | Lower Saxony |
| Chaos Computer Club Frankfurt e.V. | Hesse |
| Chaos Computer Club München e.V. | Bavaria |
| Chaos Consulting e.V. | |