| Custos Media Technologies (RF) (Pty) Ltd | Western Cape |
| Cyber Ads | |
| Cyber Connect | Gauteng |
| Cyber Range | Gauteng |
| CyberDevs | Free State |
| Cyberlab CC | Gauteng |
| Cybersmith Web Dev | KwaZulu-Natal |
| Cybersolve (Pty) Ltd | |
| Cyberstom Website Design | Gauteng |
| CyberSupport CC | KwaZulu-Natal |
| Cybertek | KwaZulu-Natal |
| CyberTracker Conservation | Western Cape |
| Cybicom Technologies | |
| Cylon Technology (Pty) Ltd | Gauteng |
| CyperPro Consulting | Western Cape |
| D-Bit Systems | Gauteng |
| D-Link South Africa | Gauteng |
| D3signs Creative Studio | Western Cape |
| DAC Systems | Gauteng |
| Daily Dose Marketing | |
| Daita | |
| Damelin (Pty) Ltd | |
| Damion-Lee Caldicott | Western Cape |
| DankoSpark | |
| DanzLive | |
| Dariel | |
| Data Video Communications (Pty) Ltd | Gauteng |
| Data World | KwaZulu-Natal |
| Data-Shack | |
| Databias | Western Cape |
| Datacentrix Holdings Ltd | Gauteng |
| Datacraft Software | Gauteng |
| DataDetect | Gauteng |
| Datafin | Western Cape |
| Datakey Group | Western Cape |
| Dataprophet | Western Cape |
| DataRecover | Gauteng |
| Datasmith | Western Cape |
| Datasp | Gauteng |
| DataSwift Software | Western Cape |
| Datatex Dynamics | Western Cape |
| Dataweek | Gauteng |
| dataX | Western Cape |
| David Digital IT Solutions | Mpumalanga |
| Dax Data | Western Cape |
| DC Media S.A. (Pty) Ltd | Gauteng |
| DC3 Distribution | Western Cape |
| DcData | KwaZulu-Natal |
| DCHost Pty Ltd | Gauteng |
| DeARX Services | Gauteng |