| Gun Interactive | United States | — | — | 2 |
| Gunfire Games | — | July 31, 2014 | 2 | — |
| GungHo Online Entertainment | Japan | July 1998 | 8 | 12 |
| Gunstone Studios | El Salvador | 2018 | 1 | — |
| Gust Co. Ltd. | Japan | October 1993 | 30 | 2 |
| Guyzware Inc. | Japan | March 3, 2006 | 1 | — |
| H.a.n.d. | Japan | February 26, 1993 | 10 | — |
| H2 Interactive | South Korea | September 4, 2009 | — | 1 |
| Haemimont Games | Bulgaria | September 1997 | 9 | 1 |
| Hakama | Japan | 2018 | 2 | — |
| HAL Laboratory | Japan | February 21, 1980 | 58 | 10 |
| Half Mermaid Productions | United States | 2017 | 1 | 1 |
| Half Past Yellow | Denmark | — | 1 | — |
| Halfbot | — | 2010 | 1 | — |
| Halfbrick Studios | Australia | 2001 | 10 | 5 |
| Halo Studios | United States | 2009 | 7 | — |
| Halycon Media | Germany | — | 1 | — |
| Hamham-soft | Japan | — | 2 | 1 |
| Hammer & Ravens | Estonia | 2015 | 2 | 1 |
| Hamster Corporation | Japan | November 11, 1999 | 14 | 26 |
| Hamster On Coke Games | Poland | April 2012 | 1 | 1 |
| Han-Squirrel Studio | People's Republic of China | — | 1 | — |
| Hanako Games | United Kingdom | 2003 | 3 | 3 |
| HanbitSoft | South Korea | 1999 | 1 | — |
| Handheld Games | United States | — | 2 | — |
| Hands-On Mobile | United States | 2001 | 1 | 3 |
| Hangonit Studio | Czech Republic | — | — | 1 |
| Hap inc. | Japan | March 6, 2007 | 1 | 1 |
| Happy Broccoli Games | Germany | — | 3 | 2 |
| Happy Happening | — | 2001 | 1 | — |
| Happy Juice Games | Israel | — | 1 | — |
| Happy Life Animation | Sweden | — | — | 1 |
| Happy Volcano | Belgium | 2017 | 1 | 1 |
| HAPPYTUK Co., Ltd. | Taiwan | June 13, 2012 | — | 1 |
| Hardlight | — | 2012 | 5 | — |
| Harebrained Schemes | United States | 2011 | 6 | — |
| Harmonix Music Systems | United States | 1995 | 27 | 4 |
| Hasbro | United States | 1923 | — | 2 |
| Hasbro Interactive | United States | 1995 | 4 | 18 |
| Hatinh Interactive | France | February 24, 2020 | — | 1 |
| HB Studios | Canada | 2000 | 8 | 1 |
| Headbang Club | France | December 22, 2016 | — | 1 |
| Headfirst Productions | United Kingdom | 1998 | 1 | — |
| Headlock | Japan | December 10, 1999 | 1 | — |
| Headstrong Games | United Kingdom | 2008 | 2 | — |
| Headup Games | Germany | 2009 | 1 | 33 |
| Headware Games | United Kingdom | — | 1 | — |
| Heart Machine | United States | 2013 | 1 | — |
| Heart Shaped Games | United States | — | 1 | 1 |
| Heartbeat | Japan | October 1992 | 2 | — |
| Heartomics | United States | — | 4 | 4 |
| Heavy Iron Studios | United States | 2005 | 5 | — |
| Hect | Japan | 1988 | — | 1 |
| Helixe | United States | July 2000 | 1 | — |
| Hellbent Games | Canada | 2006 | 5 | 2 |
| Hello There Games | Sweden | — | 1 | — |
| Her Interactive | United States | 1995 | 36 | 14 |
| Hermes Interactive | Denmark | 2016 | 2 | 1 |
| Herobeat Studios | Spain | — | 1 | — |
| HeroCraft | Cyprus | 2002 | 3 | 4 |
| HESware | United States | 1980 | — | 1 |
| Heureka-Klett-Softwareverlag | Germany | — | — | 2 |
| Heuristic Park | United States | 1995 | 1 | — |
| Hewson Consultants | United Kingdom | 1984 | — | 2 |
| HexaDrive | Japan | February 2007 | 6 | 1 |
| HexWar Games | United Kingdom | — | 5 | 5 |
| Hezbollah | Lebanon | 1982 | — | 1 |
| Hi Tech Expressions | United States | 1988 | — | 3 |
| Hi-Rez Studios | United States | 2005 | 3 | 4 |
| Hibernum Créations Inc. | Canada | 2006 | 1 | — |
| Hidden Fields | Switzerland | — | 1 | — |
| Hidden Path Entertainment | United States | 2006 | 10 | 7 |
| Hidden Trap | Spain | — | — | 1 |
| Higgs Games | Germany | — | 1 | 1 |
| High Impact Games | United States | 2003 | 4 | — |
| High Moon Studios | United States | 2001 | 7 | — |
| High Tea Frog | United Kingdom | — | 1 | 1 |
| High Voltage Software | United States | 1993 | 19 | 1 |
| Hikari Field | Japan | July 2016 | — | 12 |
| Himalaya Studios | United States | — | 1 | 1 |
| Hip Interactive | Canada | 1995 | — | 1 |
| HipSoft | United States | — | 4 | — |
| Historia | Japan | October 31, 2013 | 4 | 2 |
| Hit-Point | Japan | — | 6 | — |
| HitGrab | — | — | 1 | 1 |
| Hodder & Stoughton Limited | United Kingdom | 1868 | — | 1 |
| Holistic Design | United States | 1992 | 3 | — |
| Holy Wow | United States | — | 1 | 1 |
| Home Entertainment Suppliers | — | 1984 | — | 1 |
| Honey Parade Games | Japan | — | 6 | 1 |
| Hooded Horse | United States | — | — | 3 |
| Hook | Italy | July 23, 2020 | 1 | 1 |
| Hooksoft | Japan | 2000 | 3 | 2 |
| Hoolai Games | People's Republic of China | 2008 | 1 | 1 |
| HopFrog | Argentina | — | — | 1 |
| Hoplite Research | United States | — | 1 | 1 |
| Hopoo Games, LLC | United States | 2012 | 3 | — |
| Horrible Guild Games | Italy | 2014 | 1 | 1 |
| Hot B | Japan | 1983 | 1 | 2 |
| Hot Lava Games | United States | 2005 | 3 | — |