| Nubilum Games | Developer | |
| Nuchallenger | DeveloperPublisher | |
| Nuclear Beans | Developer | |
| Nuclear Fishin' Software | Developer | |
| Nuclear Meltdown Productions | Publisher | |
| Nuclear Monkey Software | Developer | |
| Nuclear Strawberry | Developer | |
| Nuclear Tales | Developer | |
| Nuclear Toaster | Developer | |
| NuclearFriend | Developer | |
| NuclearVision | Developer | |
| Nuclear_Diamond | Developer | |
| Nucleose | Developer | |
| Nucleosys | Developer | |
| Nuclide Games | Developer | |
| Nude Maker | Developer | |
| Nudiventra | Developer | |
| NueSB | Developer | |
| Nueve | Developer | |
| Nuevo Retro Games | Developer | |
| Nufekop | Developer | |
| NughtaedGames | Developer | |
| Nuhn | Developer | |
| Nui | Developer | |
| Nujum Key | Developer | |
| NukadukeParipiMan | Developer | |
| Nuke Fist | Developer | |
| Nukleud | Developer | |
| Null Reference | Developer | |
| Null Reference Games | Developer | |
| Null Studios | Developer | |
| Null Tale | Developer | |
| Null&Void | Developer | |
| NullSetGames | Developer | |
| Nullify | Developer | |
| Num_T | Developer | |
| Numachi Tamanegi | Developer | |
| Numantian Games | Developer | |
| Number None | DeveloperPublisher | |
| Number None, Inc. | Developer | |
| Number77 | Developer | |
| Numbuh474 | Developer | |
| Numeritos21 | Developer | |
| Numeron | Developer | |
| Numerus | Developer | |
| Numizmatic | DeveloperPublisher | |
| Numskull Games | DeveloperPublisher | |
| NunFuel | Developer | |
| Nunchuck Games | Publisher | |
| Nuninho Neto | Developer | |
| Nuno Ribeiro | Developer | |
| Nunukin | Developer | |
| Nupixo Games | Developer | |
| Nupsi | Developer | |
| Nurator | Developer | |
| NuraxInteractive | Developer | |
| Nurbs Studios | Developer | |
| Nurijoy | Developer | |
| Nurimunibuni | Developer | |
| Nurium Games | DeveloperPublisher | |
| Nurogames | Developer | |
| Nuskadamo | Developer | |
| Nusso | Developer | |
| Nussoft | DeveloperPublisher | |
| Nutr1z | Developer | |
| Nuttery Entertainment | Developer | |
| Nutting Associates | Publisher | |
| Nutty Fox Studio | Developer | |
| Nuubman | Developer | |
| Nuvision Entertainment | Publisher | |
| Nuxill | Developer | |
| Nv7 | Developer | |
| Nvizzio Creations | Developer | |
| NvrSkipGameDay | Developer | |
| Nvriezen | DeveloperPublisher | |
| NyaXxProduction | Developer | |
| Nyacu | Developer | |
| Nyamakop | DeveloperPublisher | |
| Nyamyam | DeveloperPublisher | |
| Nyan | DeveloperPublisher | |
| NyanBacon | Developer | |
| NyanGames | Developer | |
| NyanZak | Developer | |
| Nyar | Developer | |
| Nyat | Developer | |
| Nydium Games | Developer | |
| Nyeti | Developer | |
| Nyguren | Developer | |
| NykTV | Developer | |
| NykolaR | Developer | |
| Nylash | Developer | |
| Nylon Blonde | Developer | |
| NymnWales | Developer | |
| Nyrator | Developer | |
| Nyyy | Developer | |
| Nzquare | Developer | |
| Núria | Developer | |
| O Game Development | Developer | |
| O Part | Developer | |
| O Programador | Developer | |
| O-A-K | Developer | |
| O-Games | DeveloperPublisher | |
| O-GamesNA | Publisher | |
| O-TWO | Developer | |
| O.Y.G | Developer | |
| O2 Games | DeveloperPublisher | |
| O2 Online Entertainment | DeveloperPublisher | |
| O3 Entertainment | Publisher | |
| O3 EntertainmentNA | Publisher | |
| O3 Games | Developer | |
| OAB | Developer | |
| OAI | Developer | |
| OCC | DeveloperPublisher | |
| ODIAX | Developer | |
| ODIN Software | DeveloperPublisher | |
| ODS | Developer | |
| ODenis Studios | Developer | |
| OG International Ltd | Publisher | |
| OG-M | Developer | |
| OGD | Developer | |
| OGDarkWolfie | Developer | |
| OGPlanet | Publisher | |
| OGUREC APPS | Developer | |
| OG_Hamster | Developer | |
| OHISASHI | Developer | |
| OIDyre | Developer | |
| OKSoft | Developer | |
| OKYOGames | Developer | |
| OLEANDER GARDEN | Developer | |
| OLEANDRIN | Developer | |
| OLGA | Developer | |
| OLKO | Developer | |
| OLM | Developer | |
| OM M | Developer | |
| OMGWTFGAMES!1!! | Developer | |
| OMI Games | Developer | |
| OMK Software | DeveloperPublisher | |
| OMOCAT | Developer | |
| OMega Mikotto | Developer | |
| ON3D Studios | Developer | |
| ONCGM | Developer | |
| OOO Valnat | Publisher | |
| OOTP Developments | DeveloperPublisher | |
| OP Games | Developer | |
| OPENsupermen | Developer | |
| OPQAM | Developer | |
| OPeNBooK | DeveloperPublisher | |
| OPeNBooK Co., Ltd. | Developer | |
| OPeNBooK9003 | DeveloperPublisher | |
| ORIGIN Systems | Developer | |
| ORT Software | DeveloperPublisher | |
| OSC | Publisher | |
| OSP Enr. | DeveloperPublisher | |
| OSR | Developer | |
| OSTA | Developer | |
| OSome Studios | Developer | |
| OTGDev | Developer | |
| OTLGame | Developer | |
| OUAT Entertainment | Developer | |
| OVERBOY ツ | Developer | |
| OX | Developer | |
| OXTORD games | Developer | |
| OXiAB Game Studio | DeveloperPublisher | |
| OZ Club | DeveloperPublisher | |
| Oachkatzl | Developer | |
| OakLeafGames | Developer | |
| OakiDev | Developer | |
| Oakleaff | Developer | |
| OakleyBlade | Developer | |
| Oaks Soft | Developer | |
| Oaktown Studios | Developer | |
| Oaky Games | Developer | |
| Oasis Games | Publisher | |
| Oasis Plus | Developer | |
| OatCube | Developer | |
| OatsCreative | Developer | |
| Obaasan Games | Developer | |
| ObakeNekoWorks | Developer | |
| Obelix | Developer | |
| ObentoMori | Developer | |
| Obeonix | Developer | |
| Oberon Media | Publisher | |
| Obi-Gun Kenobi | Developer | |
| ObiSam2017 | Developer | |
| Object Software | Developer | |
| Object Software Limited | Developer | |
| Objectif 3D | Developer | |
| Objectively Big | Developer | |
| Obo Games | Developer | |
| Obscurata_Studios | Developer | |
| Obscure Tales | Developer | |
| Obsessive Science Games | Developer | |
| Obside | Developer | |
| Obsidian Entertainment | Developer | |
| ObsidianBlk | Developer | |
| Obsyds's Game | Developer | |
| Obunsha | DeveloperPublisher | |
| OcO | Developer | |
| Ocarina System | Developer | |
| OccOcGame | Developer | |