| Cyberhouse GmbH & Co. KG | Upper Austria |
| Cyberith GmbH | |
| Cybertec PostgreSQL International GmbH | Lower Austria |
| CYBERTRAP Software GmbH | |
| CyberTron Telekom AG | Vienna |
| CycloTech GmbH | |
| Cycuria Therapeutics | |
| Cyprumed GmbH | |
| D-Seven, Design und Werbeagentur e.U. | Vienna |
| DADAT | |
| Danube Private University | |
| Danube Tech GmbH | |
| Darwin’s Lab GmbH | |
| Das Comitee GmbH | |
| Das Packhaus | |
| Data Dealer | Vienna |
| Data.gv.at | Vienna |
| Datadialog.net | |
| Datadive | Vienna |
| dataformers GmbH | |
| Datagnion GmbH | |
| Dataphone GmbH | Vienna |
| DataScience Service GmbH | |
| Datavisyn GmbH | |
| Dataware Handelsges.m.b.H. | Lower Austria |
| Datenkraft GmbH | Styria |
| DatenVorsprung GmbH | |
| dawn-bio GmbH | |
| daz Design und Grafik e.U. | Tyrol |
| DBConcepts GmbH | Vienna |
| DCCS GmbH | Styria |
| DealMatrix GmbH | |
| Decidio GmbH | |
| Deckweiss GmbH | |
| DECOM Softwareentwicklung GmbH & Co. KG | Upper Austria |
| DeepOpinion | |
| Delegate Technology GmbH | Vienna |
| Delta 4 GmbH | |
| Demmel Products GmbH | Vienna |
| Denovo GmbH | |
| Der querdenker | Salzburg |
| DerAutomat Harrer GmbH & Co. KG | |
| DESC Handels Gesellschaft m.b.H. | Styria |
| Designify | |
| Designkanzlei | Vienna |
| Designtiger | Vienna |
| DeskCalc GbR | Styria |
| DeskSoft | Vienna |
| DevOps Squad OG | |
| Dewetron GmbH | Styria |