| Nintendo System Development | Japan | 1997 | 4 | — |
| Nippon Columbia | Japan | October 1910 | 2 | 1 |
| Nippon Computer Systems | Japan | December 25, 1980 | 9 | 5 |
| Nippon Cultural Broadcasting Extend | Japan | May 11, 2012 | 1 | 1 |
| Nippon Ichi Software | Japan | July 12, 1993 | 31 | 49 |
| NIS America | United States | December 24, 2003 | — | 31 |
| Nitro chiral | Japan | 2004 | 2 | 2 |
| Nitro Games | Finland | 2007 | 2 | — |
| Nitrome | United Kingdom | August 10, 2004 | 2 | 3 |
| Nitroplus | Japan | 2000 | 6 | 4 |
| Nival | Russia | 1996 | 19 | 6 |
| Nixxes Software | Netherlands | August 1999 | 7 | — |
| NMK | Japan | May 1989 | 8 | 2 |
| No Gravity Games | Poland | 2016 | — | 24 |
| No More Robots | United Kingdom | — | — | 11 |
| Nobilis | France | May 15, 2001 | — | 2 |
| Noir Soft | Japan | — | 1 | 1 |
| Noise | Japan | 1996 | 5 | — |
| Noise Factory | Japan | 1998 | 3 | — |
| Nokia | Finland | May 12, 1865 | — | 3 |
| Nomad Games | United Kingdom | 2011 | 5 | 6 |
| Nomada Studio | Spain | — | 1 | — |
| Noobz from Poland | Poland | — | 1 | — |
| Noodlecake | Canada | 2011 | 4 | 12 |
| Nordcurrent | Lithuania | 2002 | 3 | 4 |
| Norsk Strek | Norway | — | — | 1 |
| North Kingdom | Sweden | May 19, 2003 | 3 | — |
| Northplay | Denmark | — | 2 | 2 |
| Nosebleed Interactive | United Kingdom | May 29, 2012 | 1 | — |
| Nosotek | North Korea | 2008 | 1 | — |
| Nostatic Software | United States | — | 10 | 10 |
| Not a Sailor Studios | United States | — | 1 | — |
| Nova-Box | France | 2007 | 1 | 1 |
| Novagen Software | United Kingdom | 1984 | 1 | — |
| Novarama | — | July 3, 2003 | 6 | — |
| NOVECT | Japan | — | 1 | — |
| Noviy Disk | Russia | 1997 | — | 8 |
| Novotrade | Hungary | January 6, 1983 | 1 | — |
| Now Production | Japan | June 17, 1986 | 10 | — |
| Nowcom | — | 1994 | — | 1 |
| Npckc | Japan | — | 4 | 3 |
| NStigate Games | United States | March 1998 | 1 | — |
| NTDEC | — | 1983 | 1 | 1 |
| Ntreev Soft | South Korea | 2003 | 1 | — |
| Nucleosys | Argentina | 2003 | 1 | — |
| Nude Maker | Japan | 2002 | 1 | — |
| NuFX | United States | 1990 | 1 | — |
| NukGames | Brazil | — | 4 | 3 |
| Nupixo Games | Canada | — | 1 | 1 |
| Nutaku | Canada | 2014 | — | 1 |
| Nutting Associates | — | 1965 | 1 | 1 |
| Nuuvem | Brazil | — | — | 1 |
| Nuverse | People's Republic of China | 2019 | — | 2 |
| Nvidia | United States | April 5, 1993 | — | 1 |
| Nyu Media | United Kingdom | 2011 | — | 1 |
| Nôrdika Studio | Canada | — | 1 | — |
| O.T.K Games | People's Republic of China | June 2014 | 1 | — |
| O3 Entertainment | United States | 2004 | — | 1 |
| Oasis Games | People's Republic of China | 2011 | — | 2 |
| Oberon Media | United States | 2003 | 2 | 3 |
| Obsidian Entertainment | United States | June 12, 2003 | 10 | — |
| Ocean Software | United Kingdom | 1983 | 12 | 23 |
| Oddboy | New Zealand | 2016 | 1 | 1 |
| Oddworld Inhabitants | United States | 1994 | 6 | 2 |
| Odyssey Interactive | Canada | — | 1 | 1 |
| Offbrand Games | United States | June 7, 2024 | — | 1 |
| Office Create | Japan | April 3, 1990 | 1 | — |
| Offworld Industries | Canada | February 2015 | 1 | 2 |
| Ogre Pixel | Mexico | — | 1 | 1 |
| Oh, a Rock! Studios | United States | March 24, 2014 | 4 | 4 |
| Ohio Distinctive Software | United States | — | 3 | — |
| Ohsat Games | Germany | — | 1 | — |
| Oink Games | Japan | — | 1 | 1 |
| Oizumi Amuzio | Japan | — | — | 1 |
| Old Skull Games | France | January 20, 2015 | 4 | — |
| OLM, Inc. | Japan | June 1994 | 1 | — |
| Omega Force | Japan | 1996 | 25 | — |
| One Compath | Japan | January 20, 1997 | — | 1 |
| One More Level | Poland | 2014 | 3 | 1 |
| One O One Games | Italy | 2019 | 1 | — |
| One Up Plus | Australia | — | 1 | — |
| Ongakukan | Japan | September 1985 | 1 | 1 |
| Onion Games | Japan | — | 1 | 1 |
| OnSkull Games | Greece | — | 8 | 8 |
| OperaHouse | Japan | April 2002 | 1 | — |
| Oracle Corporation | United States | June 16, 1977 | — | — |
| Orange Pixel | Netherlands | — | 7 | 6 |
| Orbital Knight | Poland | 2012 | 2 | — |
| ORCA | Japan | — | 1 | — |
| Orcsoft | Japan | 2009 | 1 | — |
| Origamihero Games | Austria | — | 4 | 4 |
| Origin Systems | United States | 1983 | 21 | 10 |
| Orion Pictures | United States | 1978 | — | 1 |
| Orthrus Studios | United Kingdom | 2017 | 1 | — |
| Orube Game Studio | Brazil | — | 2 | 2 |
| Osgoode Media | United States | 2016 | 1 | 1 |
| Osmotic Studios | — | — | 2 | — |
| OSome Studio | France | April 10, 2013 | 3 | — |
| Ossian Studios | — | 2003 | 2 | — |
| Other Ocean | United States | 2006 | 7 | — |