| Careers in Space Pty Ltd | New South Wales |
| CargoWise | |
| Carina Biotech | South Australia |
| Carisma Solutions | |
| Carl Chapman | Queensland |
| Carlton Digital | |
| Carma | |
| Carnegie Mellon University in Australia | South Australia |
| Carringbush.Net | Victoria |
| Carter Experience Agency | |
| Cartherics Pty Ltd | Victoria |
| Carthona Capital AFS | New South Wales |
| Cartridges Direct | Victoria |
| CartridgeSpecialists.com.au | Victoria |
| Caruso Software Ltd | |
| CAS Netlink (Aust) Pty Ltd | Victoria |
| Cascade | New South Wales |
| Case Management Society of Australia | Queensland |
| Cash Focus | New South Wales |
| Cashpoint ATM Company | New South Wales |
| Castaway Forecasting | New South Wales |
| Catalyst IT Australia Pty Ltd | New South Wales |
| Catalyst Media | Queensland |
| Catalyst Strategic | Victoria |
| Catchy Pages | New South Wales |
| Cathco Consultancy Pty Ltd | Queensland |
| Cazazz | Queensland |
| CBDWeb | Victoria |
| CBE Pure Solutions | Victoria |
| CBIT Internet & Hosting | Australian Capital Territory |
| CBL Data Recovery Technologies Pty Ltd | Queensland |
| CBM Computers | New South Wales |
| CBS Management Systems | South Australia |
| CBS Software | South Australia |
| CD-ROM Services Australia | New South Wales |
| Cell Therapies Pty Ltd | |
| Cellink | New South Wales |
| Cellnet Group Ltd | Queensland |
| Celosia Therapeutics | |
| Cenofex Innovations | New South Wales |
| Centaur Software Development Co. | New South Wales |
| Centenary Institute of Cancer Medicine and Cell Biology | |
| 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 Adult Education | |
| Centre for Digestive Diseases | |