| Deck Computer Services | Western Cape |
| Deep Blue | Gauteng |
| Deep Current | KwaZulu-Natal |
| Defcon5 Electronic Services | Gauteng |
| DefenceWeb | Gauteng |
| Definite Web Hosting (Pty) Ltd | Gauteng |
| Delegate IT | |
| Deltalink Consulting | Gauteng |
| Delter | Gauteng |
| Department of Communications, Republic of South Africa | Gauteng |
| Department of Telecommunications & Postal Services | Gauteng |
| Design Connection | Western Cape |
| Design from Cape Town | |
| Design Guru | Western Cape |
| Design Odyssey | |
| Designs by J9 | |
| Designtalks | |
| Desktop Group | Gauteng |
| DesSoft | Gauteng |
| DETA IT Business | Gauteng |
| Dev InfoTec (Pty) Ltd | Gauteng |
| Develec CC | Western Cape |
| Development IT Solutions CC | Gauteng |
| DevEnterprise Software | KwaZulu-Natal |
| Device SA | Gauteng |
| DevIgnite | |
| DevLabs CC | Western Cape |
| Devoir | |
| DevOps Business | |
| Dezign-IT | |
| Dezina Web | Gauteng |
| Dial a Nerd | Gauteng |
| DialSA | Western Cape |
| DiaMatrix | Gauteng |
| Diarize Me | Western Cape |
| Digiata Technologies | Western Cape |
| Digibility | Gauteng |
| Digicape | Western Cape |
| Digify Africa | Gauteng |
| DigiMarCon Africa | |
| DigiMarCon South Africa | |
| DiginamiX | |
| Digineering | Gauteng |
| DigiServ | Gauteng |
| Digital Angel | |
| Digital Apex (Pty) Ltd | |
| Digital Consulting | |
| Digital Distributors | Western Cape |
| Digital Dynamix | Eastern Cape |
| Digital Fold | |