| CMO Australia | New South Wales |
| CO-HAB | South Australia |
| Coassemble | New South Wales |
| Codan Radio Communications | South Australia |
| Codarra Advanced Systems Pty Ltd | New South Wales |
| Code Academy | Queensland |
| CodeFish Studio | South Australia |
| Codemaster Institute | Western Australia |
| Codevelopment Pty Ltd | Western Australia |
| Cogentis Pty Ltd | New South Wales |
| Coghlan Pty Ltd | New South Wales |
| Cohda Wireless | South Australia |
| Cohort Innovation Space | Queensland |
| COHUTT | South Australia |
| CoinJar | Victoria |
| Cointree Pty Ltd | Victoria |
| Collective Campus | Victoria |
| Coloplast | |
| Com Net Solutions Pty Ltd | New South Wales |
| Command Computers | New South Wales |
| Command Software Pty Ltd | Queensland |
| Commandacom | Western Australia |
| CommandHub Pty Ltd | Victoria |
| Commerce Plus Pty Ltd | New South Wales |
| Common Sense Ventures | Victoria |
| Commonwealth Bank of Australia | New South Wales |
| CommsChoice | New South Wales |
| Commsday | New South Wales |
| CommsNet Group | Australian Capital Territory |
| CommTel Network Solutions | Victoria |
| Communicat Business Systems | Victoria |
| Communications Alliance Ltd | New South Wales |
| Communications Design & Management | New South Wales |
| Compare and Merge | South Australia |
| CompeteShark | New South Wales |
| Complas Web Design & Hosting | Victoria |
| Complete Cloud | New South Wales |
| Complete Data Recovery | Victoria |
| Complete PC Solutions | Victoria |
| Complete Phase Consulting | Victoria |
| Complete Phase CRO | Victoria |
| Compliance Quarter | |
| Complii FinTech Solutions Ltd | New South Wales |
| Compoint Computers | New South Wales |
| ComponentSpace | Queensland |
| Compu-Stor | Western Australia |
| Compucon Computers SA Pty Ltd | South Australia |
| Compumedics Ltd | Victoria |
| Compusoft Australia Pty Ltd | New South Wales |
| Computer Aid | Queensland |