| Intel | United States | July 18, 1968 | 2 | 1 |
| Intelligent Games | United Kingdom | 1988 | 5 | — |
| Intelligent Systems | Japan | December 1986 | 58 | — |
| INTENSE | Japan | July 2002 | 2 | — |
| Intense Limited | Japan | July 2002 | 1 | 1 |
| Interactive Data Visualization Inc. | — | 2000 | — | — |
| Interactive Magic | United States | 1994 | 1 | 4 |
| Interactive Television Entertainment | — | 1988 | 5 | 1 |
| Interchannel | Japan | 1987 | — | 5 |
| Intergalactic Development | United States | — | 3 | — |
| Interheart | Japan | 1992 | — | 1 |
| International Fencing Federation | — | November 29, 1913 | — | 1 |
| International Games System | Taiwan | October 1991 | 2 | 1 |
| Interplay Entertainment | United States | October 1983 | 17 | 49 |
| InterServ International Inc | Taiwan | April 18, 1989 | 1 | — |
| Interstel Corporation | United States | — | — | 1 |
| Inti Creates | Japan | May 8, 1996 | 29 | 12 |
| IntraCorp | United States | 1984 | — | 3 |
| Introversion Software | United Kingdom | 2001 | 1 | 1 |
| Invader Studios | Italy | July 2016 | 2 | — |
| Invictus Games | Hungary | 2000 | 7 | 2 |
| InXile entertainment | United States | 2002 | 7 | 5 |
| IOMO | — | 2000 | 1 | — |
| Ion Storm | United States | 1996 | 3 | — |
| IQ Media Nordic | Sweden | April 21, 1992 | — | 2 |
| Irem | Japan | 1974 | 24 | 22 |
| Iron Galaxy Studios | United States | 2008 | 8 | — |
| Iron Gate Studio | Sweden | April 2019 | 1 | — |
| Iron Lore Entertainment | United States | October 2000 | 2 | — |
| Ironclad Games | — | 2003 | 2 | — |
| Ironhide Game Studio | Uruguay | January 26, 2010 | 8 | 7 |
| Ironhide Ireland Limited | Ireland | October 28, 2020 | — | 1 |
| Ironwood Studios | United States | — | 1 | — |
| Irrational Games | United States | 1997 | 6 | — |
| ISCO | Japan | 1987 | 1 | — |
| Ishtar Games | France | August 2005 | 2 | 1 |
| Isto Inc. | Canada | January 19, 2018 | 1 | 1 |
| It Matters Games | Germany | — | 4 | — |
| IV Productions | Italy | — | — | 13 |
| Ivanoff Interactive | Denmark | 1996 | 18 | 10 |
| IWare Designs | United Kingdom | September 24, 2010 | 1 | 1 |
| IzanagiGames | Japan | — | 1 | 2 |
| J.P ROOM Inc | Japan | August 29, 2001 | 1 | — |
| Jackbox Games | United States | 2008 | 15 | 13 |
| Jadestone Group | Sweden | 1999 | 1 | 1 |
| Jagex | United Kingdom | 2001 | 6 | 6 |
| Jaibo Games | Ukraine | 2007 | 3 | — |
| Jakks Pacific | United States | 1995 | 1 | 1 |
| Jaleco | Japan | July 3, 2006 | 12 | 29 |
| Jaleco USA | United States | 1988 | — | 1 |
| Jam City | — | 2010 | 1 | — |
| JAM Productions | United States | 1993 | 1 | — |
| JanduSoft | Spain | 2012 | 2 | 27 |
| Japan Art Media | Japan | November 9, 1989 | 3 | — |
| Japan Media Programming Inc. | Japan | — | 1 | — |
| Japan Studio | Japan | November 16, 1993 | 17 | 3 |
| JAST USA | United States | 1997 | — | 16 |
| Javaground | United States | 2001 | 1 | — |
| Jellyfish | Japan | — | 1 | 1 |
| Jellyvision | United States | 1989 | 1 | — |
| Jester Interactive | United Kingdom | 1997 | 1 | — |
| Jet Black Games | Canada | 2007 | 1 | — |
| Jetdogs Studios | Finland | 2015 | 32 | 31 |
| Jinthree Studio | South Korea | — | 1 | 1 |
| JM Neto Game Dev | Brazil | — | 2 | 2 |
| Joindots | Germany | — | 4 | 6 |
| Jolt Online Gaming | — | 1999 | 1 | — |
| Journey Bound Games | Canada | — | 1 | 1 |
| JoWooD Ebensee | Austria | — | 1 | — |
| JoWooD Entertainment | Austria | 1995 | 5 | 24 |
| JRC Czech | Czech Republic | August 5, 2003 | — | 2 |
| Juggler Games | Poland | 2015 | 2 | — |
| Jumpship | United Kingdom | January 19, 2017 | 1 | 1 |
| Junction Point Studios | United States | 2005 | 2 | — |
| Jundroo | United States | — | 2 | 2 |
| Jupiter | Japan | June 11, 1992 | 34 | 24 |
| Just Add Water | United Kingdom | 2006 | 1 | — |
| Just for Games | France | January 12, 2011 | — | 4 |
| Jutsu Games | Poland | — | 3 | — |
| JV Games | United States | 1994 | 1 | — |
| JVC | Japan | September 13, 1927 | 1 | 4 |
| K Bros Games | United States | — | 1 | 1 |
| K-D Lab | Russia | 1995 | 7 | — |
| K. Amusement Leasing Co. | Japan | 1972 | 1 | 1 |
| Kabam | United States | 2006 | 2 | 2 |
| Kadokawa Corporation | Japan | 2014 | — | — |
| Kadokawa Games | Japan | April 2009 | 2 | 11 |
| Kadokawa Key-Process | Japan | 1954 | 5 | 2 |
| Kadokawa Shoten | Japan | November 10, 1945 | 3 | 16 |
| Kaga Create | Japan | June 22, 1988 | 2 | 5 |
| Kairosoft | Japan | September 2007 | 18 | 18 |
| Kaizen Game Works | United Kingdom | 2018 | 1 | — |
| Kakao Games | South Korea | — | — | 4 |
| Kalisto Entertainment | France | 1992 | 3 | — |
| Kalypso Media | Germany | 2006 | — | 26 |
| Kamibox | Germany | — | 2 | 1 |
| Kaneda Games | Spain | — | 2 | — |
| Kaneko | Japan | June 25, 1980 | 1 | 2 |
| Kaos Studios | United States | 2006 | 1 | — |
| Karoshi Corporation | Spain | 2003 | 1 | — |