| Conflated Solutions (Pty) Ltd | KwaZulu-Natal |
| Connectivity Database Technologies | Gauteng |
| Conor Information Technology (Pty) Ltd | Gauteng |
| Conqueror Technologies | Gauteng |
| Consnet | Gauteng |
| Context Solutions | Western Cape |
| Contour Online | Gauteng |
| Contour Technology (Pty) Ltd | Gauteng |
| Control Software Solutions (Pty) Ltd | KwaZulu-Natal |
| Controlled Power Company | Gauteng |
| Contron IT | Gauteng |
| Convergence Partners | Gauteng |
| Conversation Lab | |
| Converted Click | |
| CopperTable | |
| Core Group | Gauteng |
| Cornerstone Institute | |
| Cortell | Gauteng |
| Cosimo Web and Design (Pty) Ltd | |
| Cosmic Link | Gauteng |
| Council for Scientific and Industrial Research in South Africa | |
| COZA Web Design | Gauteng |
| Cozan Consulting | Western Cape |
| Cradle Technology Services (Pty) Ltd | Western Cape |
| Cranefield College | |
| Craythorne Enterprises | Western Cape |
| Crazyeye Productions | Gauteng |
| Cream Graphic Design | Gauteng |
| Create4u | Western Cape |
| Creation Labs | |
| Creative Confusion Media | Western Cape |
| Creative Minds | Western Cape |
| Creative Rock Technologies (Pty) Ltd | |
| Creative Rush | |
| Creative Websites | Gauteng |
| Crimson Line | Western Cape |
| Crossfin Technology | |
| CRS Technologies | Gauteng |
| Crux Pharmaceuticals | |
| CS Trüter | Gauteng |
| CSI Thabile Networking Solutions (Pty) Ltd | Gauteng |
| CSSbiDESIGN | |
| CT Systems | Gauteng |
| Cubed Cherry | |
| CubeSpace | |
| CubeZoo | |
| Currant Technologies | Western Cape |
| Curve Concepts | Gauteng |
| Custom-Cut IT Solutions | Gauteng |
| CustomScripts | Gauteng |