| Delta Partners | Dublin City Council |
| Delta Partners Ltd | |
| Design Tribe | |
| Design Wizard | |
| DesignPro Automation | |
| Dev Centre House | Dublin City Council |
| Deveire | |
| Devfair | |
| DeviceAtlas Ltd | |
| DeviceAtlas Ltd | |
| DFT Games | |
| DIDWW Ireland Ltd | Dublin City Council |
| Digi Wolf | |
| Digico | |
| Digicom | |
| Digicom | |
| Digigrow | |
| Digigrow Ltd | Dublin City Council |
| Digiprove Ltd | Fingal County Council |
| Digisoft.tv | Cork City Council |
| DIGIT Gaming Studios | Dublin City Council |
| Digital Advantage | |
| Digital Insights | |
| Digital Jet | |
| Digital Learning Institute | |
| Digital Marketing Institute | Dún Laoghaire-Rathdown County Council |
| Digital Print Hub Ltd | |
| Digital Rights Ireland | |
| Digital Sales | |
| Digital Strategy Consultants Ltd | |
| Digital Times Ltd | Dún Laoghaire-Rathdown County Council |
| DigiTally | |
| DigitalWell | |
| Digiweb Ltd | Louth County Council |
| Dimply | |
| Ding | Dublin City Council |
| Discover Digital | Limerick City and County Council |
| Discoverprint | |
| Dmac Media | Sligo County Council |
| DMC Consultancy Ltd | |
| DMC Learning | |
| DMF Systems | |
| Dogpatch Labs | Dublin City Council |
| Dönberg Electronics Ltd | Donegal County Council |
| Donegal Web Design | Donegal County Council |
| doop | Dublin City Council |
| DoSpace | |
| Dotser | Dublin City Council |
| dotU.co.uk | Roscommon County Council |
| Douglas Control & Automation | Cork City Council |