| Holy Wow | — | 1 | 1 |
| Hooded Horse | — | — | 3 |
| Hoplite Research | — | 1 | 1 |
| Hopoo Games, LLC | 2012 | 3 | — |
| Hot Lava Games | 2005 | 3 | — |
| Houghton Mifflin Harcourt | 1880 | — | 1 |
| Human Head Studios | October 1997 | 2 | — |
| HumaNature Studios | — | 1 | — |
| HumanSoft | 1994 | 2 | — |
| Humble Bundle, Inc. | March 2010 | — | 6 |
| Humble Games | — | — | 26 |
| Hypnotix | 1993 | 1 | — |
| Iam8bit | 2005 | — | 3 |
| IBM | June 16, 1911 | — | 2 |
| Icarus Studios | — | 2 | — |
| Iced Lizard Games | — | 1 | 1 |
| ICOM Simulations | March 4, 1981 | 3 | — |
| Idea Factory International | September 30, 2013 | 1 | 11 |
| IllFonic | 2007 | 2 | 2 |
| Illumix | — | 1 | 1 |
| Image Space Incorporated | 1992 | 3 | — |
| Imagic | 1981 | 3 | 2 |
| Imagineering | 1987 | 15 | — |
| ImaginEngine | 1994 | 5 | — |
| Imangi Studios | 2008 | 1 | 1 |
| Impressions Games | 1989 | 5 | 1 |
| Incinerator Studios | 2005 | 3 | — |
| Incognito Entertainment | May 1999 | 3 | — |
| Incredible Technologies | 1985 | 1 | — |
| Indie Built | 1983 | 12 | 3 |
| IndiePub | 2007 | — | 6 |
| Infinity Ward | 2002 | 9 | — |
| Infocom | June 22, 1979 | 6 | 4 |
| Ingram Entertainment Holdings Inc. | 1981 | — | — |
| Inland Productions | — | 2 | — |
| Insomniac Games | February 28, 1994 | 24 | — |
| Intel | July 18, 1968 | 2 | 1 |
| Interactive Magic | 1994 | 1 | 4 |
| Intergalactic Development | — | 3 | — |
| Interplay Entertainment | October 1983 | 17 | 49 |
| Interstel Corporation | — | — | 1 |
| IntraCorp | 1984 | — | 3 |
| InXile entertainment | 2002 | 7 | 5 |
| Ion Storm | 1996 | 3 | — |
| Iron Galaxy Studios | 2008 | 8 | — |
| Iron Lore Entertainment | October 2000 | 2 | — |
| Ironwood Studios | — | 1 | — |
| Irrational Games | 1997 | 6 | — |
| Jackbox Games | 2008 | 15 | 13 |
| Jakks Pacific | 1995 | 1 | 1 |
| Jaleco USA | 1988 | — | 1 |
| JAM Productions | 1993 | 1 | — |
| JAST USA | 1997 | — | 16 |
| Javaground | 2001 | 1 | — |
| Jellyvision | 1989 | 1 | — |
| Junction Point Studios | 2005 | 2 | — |
| Jundroo | — | 2 | 2 |
| JV Games | 1994 | 1 | — |
| K Bros Games | — | 1 | 1 |
| Kabam | 2006 | 2 | 2 |
| Kaos Studios | 2006 | 1 | — |
| Kixeye | 2007 | 1 | 1 |
| KnowWonder | 1996 | 4 | — |
| Koei Tecmo America | 2010 | — | 4 |
| Konami Digital Entertainment, Inc. | 1982 | 1 | — |
| Kongregate | 2006 | — | 2 |
| Kronos Digital Entertainment | 1993 | 2 | — |
| Kuma Reality Games | 2003 | 1 | 1 |
| LA Game Space | 2012 | — | 1 |
| Laminar Research | 1995 | 3 | 3 |
| Last Day of Work | 2002 | 5 | 5 |
| Launchworks | 2008 | — | 1 |
| LCG Entertainment, Inc. | December 27, 2018 | 1 | 1 |
| Legacy Interactive | 1998 | 5 | 4 |
| Legend Entertainment | 1989 | 5 | 3 |
| Leland Interactive Media | 1992 | 1 | — |
| Limited Run Games | 2015 | 2 | 5 |
| Linden Lab | 1999 | 1 | 1 |
| Liquid Entertainment | March 1999 | 1 | — |
| LJN | 1970 | 1 | 6 |
| Lobotomy Software | 1993 | 1 | — |
| Locomotive Games | 1997 | 5 | — |
| Looking Glass Studios | 1990 | 10 | — |
| Lucasfilm | 1971 | — | 1 |
| Lucasfilm Games | May 1982 | 16 | 62 |
| Lucky Chicken Games | 1998 | 1 | — |
| Luxoflux | 1997 | 2 | — |
| Machine Zone | 2008 | 1 | 1 |
| Macmillan Inc. | 1896 | — | 1 |
| MacPlay | 1990 | — | 7 |
| Macromedia | February 25, 1992 | — | — |
| MacSoft Games | 1993 | 4 | 5 |
| Mad Catz | 1989 | — | 1 |
| Majesco Entertainment | 1986 | 1 | 28 |
| Major League Baseball Advanced Media | June 2000 | — | 1 |
| Malfador Machinations | 1995 | 4 | 1 |
| Malibu Comics | 1986 | 1 | — |
| Masque Publishing | — | — | 3 |
| Mass Media Inc. | 1980 | 1 | — |
| Mastiff | 2002 | — | 6 |