| D-techno | — | — | — |
| D3arts.cz | Hradec Králové | 2008 | — |
| D3T | Runcorn | 2011 | — |
| Daewon Media | Seoul | 1973 | — |
| Dakko Dakko | — | — | — |
| DAMAGE STATE | — | — | — |
| Dangen Entertainment | Osaka | 2017 | video game industry |
| DangerousBob Studio | — | — | video game industry |
| Dark Energy Digital | Manchester | 1998 | — |
| Darril Arts | — | — | video game industry |
| Data Design Interactive | — | 1983 | — |
| DATA WEST | Osaka | May 26, 1986 | software development |
| Datam Polystar | Tokyo | May 30, 1990 | video game industry |
| Davilex Games | Veenendaal | 1997 | video game industry |
| DC Comics | Burbank | 1977 | publishing |
| DC Studios | Glasgow | 1999 | — |
| DCF Studios | — | — | video game industry |
| Dead Drop Studios | — | — | video game industry |
| Deadpan Games | London | — | — |
| Deep Silver | Planegg | 2002 | — |
| Deep Silver Dambuster Studios | Nottingham | 2014 | — |
| Deep Thought Software | — | — | — |
| Defrost Games | — | 2010 | video game industry |
| Delphinium Interactive | — | — | video game industry |
| Delta 4 | — | 1984 | video game industry |
| Demonware | Dublin | 2003 | video game industry |
| Denda Games | Oldenzaal | 2007 | video game industry |
| Denki | Dundee | 2000 | — |
| Dennaton Games | Gothenburg | 2012 | video game industry |
| Design Factory | Toshima | April 2, 2001 | video game industry |
| Destination Software Inc. | Moorestown | 2001 | video game industry |
| Destineer | Minnetonka | 2001 | video game industry |
| Devespresso Games | Seoul | 2014 | — |
| DevilishGames | Villena | 1998 | — |
| Devolver Digital | Austin | 2009 | video game industry |
| Dico | Tokyo | 2011 | video game industry |
| DigiPen Institute of Technology | Redmond | 1988 | — |
| Digital Continue | New York City | 2016 | video game industry |
| Digital Eel | Seattle | 2001 | video game industry |
| Digital Excess | — | — | video game industry |
| Digital Happiness | Bandung | 2013 | video game industry |
| Digital Jesters | Welwyn Garden City | September 2003 | — |
| Digital Kingdom | Vevey | 2013 | video game industry |
| Digital Pictures | San Mateo | 1991 | video game industry |
| Digital Touch | — | — | video game industry |
| DigiTales Interactive | Saarbrücken | March 11, 2019 | video game industry |
| Dimps | Osaka | March 6, 2000 | video game industry |
| Dinamic Multimedia | Pozuelo de Alarcón | 1993 | video game industry |
| Dingo Inc. | Tokyo | 1998 | video game industry |
| Dionous Games | — | July 10, 2020 | video game industry |
| Dire Wolf Digital | — | — | video game industry |
| Discovery | — | — | — |
| Disney Interactive Studios | Glendale | December 5, 1994 | video game industry |
| Disney Mobile | Palo Alto | 2000 | Mobile |
| Distinctive Software | Vancouver | 1982 | video game industry |
| DMM.com | Tokyo | November 17, 1999 | video game industry |
| Domark Software | London | 1983 | — |
| Don’t Nod | Paris | 2008 | video game publishing |
| Double Eleven | Middlesbrough | 2009 | — |
| Double Helix Games | Irvine | 2007 | video game industry |
| Double Stallion | Montreal | 2013 | video game industry |
| Douze Dixièmes | — | March 30, 2017 | computer programming |
| Dovetail Games | Chatham | 2008 | — |
| DP Games | — | — | video game industry |
| DQ Team | Chișinău | — | video game industry |
| Dragami Games | Shinagawa | May 13, 2022 | video game industry |
| Drago Entertainment | Kraków | 1998 | video game industry |
| Drakhar Studio | — | — | video game industry |
| Draknek Limited | Bristol | February 4, 2014 | — |
| Dramatic Labs | — | — | video game industry |
| Draw Distance | Kraków | 2009 | — |
| DreadXP | — | 2020 | video game industry |
| Dream Oni | Sheffield | August 12, 2019 | — |
| Dream Software | — | — | — |
| DreamCatcher Interactive | Toronto | 1996 | video game industry |
| DreamRift | Orlando | 2009 | video game industry |
| Dreamworks Interactive | — | 1995 | — |
| Dry Cactus | Paekākāriki | — | video game industry |
| DTP entertainment | Hamburg | 1995 | video game industry |
| Duality Games | Warsaw | — | video game industry |
| Dumativa | Rio de Janeiro | 2012 | video game industry |
| Dynamic Games | Mamborê | 2004 | — |