| Dedreek | Developer | |
| DedutioN | Developer | |
| DeeCeeWorks | Developer | |
| DeeGrim | Developer | |
| DeeJayLSP | Developer | |
| DeeMainiac | Developer | |
| Deeborm | Developer | |
| Deebrol | Developer | |
| Deeli Network Technology | Developer | |
| Deen Kei | Developer | |
| Deep Digital Design | Developer | |
| Deep End Games | DeveloperPublisher | |
| Deep Fried Entertainment | Developer | |
| Deep Red Games | Developer | |
| Deep River Publishing | Publisher | |
| Deep Shadows | Developer | |
| Deep Silver | DeveloperPublisher | |
| Deep Silver Dambuster | Developer | |
| Deep Silver UK | Publisher | |
| Deep Silver Vienna | Developer | |
| Deep SilverPAL | Publisher | |
| Deep SilverPAL EU | Publisher | |
| Deep Space | Developer | |
| Deep Studio | Developer | |
| Deep Thought Software (Keith A. Goodyer, Denis Hickie) | Developer | |
| Deep Thought Software (Keith A. Goodyer, Denis Hickie, Darren Melbourne) | Developer | |
| Deep Vigil Studio | Developer | |
| Deep Water | Publisher | |
| Deep-Fold | Developer | |
| Deepnight Games | Developer | |
| Deer Farm | Developer | |
| Deerbell | Developer | |
| Deerfox Games | Developer | |
| Deerpyboi | Developer | |
| Deex | Developer | |
| Deezaath | Developer | |
| Default Labs | Developer | |
| Default developer | Developer | |
| Defaultsound | Developer | |
| Defentures | Developer | |
| Defiant Ape Studios | Developer | |
| Defiant Development | DeveloperPublisher | |
| DefiantNarwhal | Developer | |
| DefinitelyNotAShark | Developer | |
| Deflorio | Developer | |
| Defo Mort | Developer | |
| DeftBlue | Developer | |
| Degica | Publisher | |
| Degica Games | Publisher | |
| Degoma | DeveloperPublisher | |