| ComputerDrive | Queensland |
| Computers Mobile | Western Australia |
| Computers+More | Tasmania |
| Computershare Ltd | |
| Computerworld Australia | New South Wales |
| ComputerWorld New Zealand | New South Wales |
| Computing Australia Group | Western Australia |
| Computit | |
| Comscentre Pty Ltd | Queensland |
| Comunet | |
| Comvergence Pty Ltd | Victoria |
| Conceiva | Victoria |
| Concept Marketing | |
| Concept Safety Systems | Queensland |
| Conceptual Creative | Queensland |
| Conetix Pty Ltd | Queensland |
| Conn3cted | |
| Connect Communications | Victoria |
| Connect Develop | |
| Connect Education | |
| Connect IT | |
| Connect Tel | Victoria |
| Connected Community Hackerspace | Victoria |
| Connected Platforms | Queensland |
| Connective Broker Services Pty Ltd | Victoria |
| Connexion Media Ltd | Victoria |
| Connexxion Pty Ltd | Australian Capital Territory |
| Considered Solutions | New South Wales |
| Console Australia Pty Ltd | Queensland |
| Constructive Software | |
| Constructive Visual | |
| ConstructRight | |
| Consulcom Pty Ltd | New South Wales |
| Consumer Electronics Suppliers’ Association | Australian Capital Territory |
| Contact Internet Solutions Pty Ltd | Australian Capital Territory |
| Contact Profiler | New South Wales |
| Contactpoint | |
| Content Snare | Queensland |
| Control Alt Elite | Victoria |
| Converge Design | Queensland |
| Convergent Consulting | New South Wales |
| Conversion Digital | |
| Convert Digital | |
| Convert Studios | |
| Converters.tv Pty Ltd | New South Wales |
| ConX | |
| CopilotHQ | |
| Copysoft | New South Wales |
| Coral Creative | |
| Cordless Dog | Victoria |