| Cloud Specialists Pty Ltd | New South Wales |
| Cloudfloat Pty Ltd | New South Wales |
| Cloudnetic | |
| Cloudstaff | New South Wales |
| Cloudthree | |
| Club Mac User Group | New South Wales |
| Clubworx | Queensland |
| Clue Corporation Pty Ltd | |
| CMather Web Development | Victoria |
| CMAX Clinical Research | |
| CMO Australia | New South Wales |
| CMTech | |
| CN Global (Pty) Ltd | |
| CNet Software Solutions | |
| Co Media | |
| Co-Creative IT | |
| CO-HAB | South Australia |
| Coassemble | New South Wales |
| Cochlear Ltd | |
| Codan Radio Communications | South Australia |
| Codarra Advanced Systems Pty Ltd | New South Wales |
| Code Academy | Queensland |
| Code and Visual | |
| Code Cabin Pty Ltd | |
| Code Heroes | |
| Code Maven Pty Ltd | |
| Code Zeno Pty Ltd | |
| CodeFish Studio | South Australia |
| CodeFish Studio | |
| CodeForge | |
| Codemaster Institute | Western Australia |
| CodeMode | |
| Codevelopment Pty Ltd | Western Australia |
| Codium Pty Ltd | |
| COG Digital | |
| COG Marketing | |
| Cogentis Pty Ltd | New South Wales |
| Coghlan Pty Ltd | New South Wales |
| Cohda Wireless | South Australia |
| Cohort Innovation Space | Queensland |
| COHUTT | South Australia |
| Collab Agency | |
| Colleagues Matrixx | |
| Collective Campus | Victoria |
| Collective Shift | |
| College of Law | |
| Coloplast | |
| Com Net Solutions Pty Ltd | New South Wales |
| Comans Services | |
| ComKey Consulting | |