| CBS Management Systems | South Australia |
| CBS Software | South Australia |
| CD-ROM Services Australia | New South Wales |
| Cell Therapies Pty Ltd | Victoria |
| Cellink | New South Wales |
| Cellnet Group Ltd | Queensland |
| Cenofex Innovations | New South Wales |
| Centaur Software Development Co. | New South Wales |
| Center for Pavament Engineering Education | |
| CentraCX | Victoria |
| Central Coast Internet | New South Wales |
| Central Communications (Alice Springs) Pty Ltd | Northern Territory |
| Central Innovation | New South Wales |
| Central Victorian Web Design | Victoria |
| Centre for Digestive Diseases | |
| Centre for Quantum Computation and Communication Technology | New South Wales |
| Centrix | New South Wales |
| Century Software Pty Ltd | New South Wales |
| Cerebiz Pty Ltd | South Australia |
| Cerebrum (Australia) Pty Ltd | Victoria |
| Certa Therapeutics | Victoria |
| Certane Group Pty Ltd | Victoria |
| Challenger Group Ltd | New South Wales |
| Chameleon Software Pty Ltd | Western Australia |
| Chamonix IT Consulting | South Australia |
| Chaos Theory Games Pty Ltd | New South Wales |
| ChargeDesk Pty Ltd | New South Wales |
| Charles Darwin University | Northern Territory |
| Charles Sturt University | New South Wales |
| Charles Sturt University - School of Computing and Mathematics | New South Wales |
| Chart Gantt | Victoria |
| Chatstack | Queensland |
| Cheap Chips | Queensland |
| CheapDomains.com.au | New South Wales |
| CheckDog | New South Wales |
| Cheltenham Group | Western Australia |
| ChiefDreamer | Queensland |
| Chimeric Therapeutics Ltd | Victoria |
| Chisel Software | South Australia |
| Choc Chip Digital | |
| ChordWizard Software Pty Ltd | New South Wales |
| Chorus Design | New South Wales |
| Chris McIntosh Design | New South Wales |
| Chriscore.net | Victoria |
| Christie Spaces Pty Ltd | New South Wales |
| Christom Pty Ltd | Victoria |
| Christopher Strong Design | Victoria |
| Chromatix | Victoria |
| ChronoBank | New South Wales |
| CIBIS International | New South Wales |