| Action Software (Oscar Gallego Sendin, Ignacio Mendez, Javier Fafula) | Developer | |
| ActionMan | Developer | |
| Actioncraft | Publisher | |
| Actionsoft | DeveloperPublisher | |
| Active | Developer | |
| Active Gaming Media | DeveloperPublisher | |
| Active Magic (Davor Magdic) | Developer | |
| Active Magic (Predrag Beciric, Aleksandar Petrovic, Vojislav Mihailovic, Predrag Milicevic) | Developer | |
| Active Minds (John Pickford, Mark R. Jones, Simon Butler, David Whittaker) | Developer | |
| Active Software | DeveloperPublisher | |
| ActiveUP Games | Developer | |
| Activision | DeveloperPublisher | |
| Activision 02 | Publisher | |
| Activision Blizzard | Publisher | |
| Activision EU | Publisher | |
| Activision EU/NA | Publisher | |
| Activision NA | Publisher | |
| Activision NA/EU | Publisher | |
| Activision O2 | Publisher | |
| Activision Publishing | Publisher | |
| Activision Publishing, Inc. | DeveloperPublisher | |
| Activision Value | DeveloperPublisher | |
| Activision Value Publishing | Publisher | |
| Activision Value Publishing, Inc. | Publisher | |
| Activision ValueAU | Publisher | |
| Activision, | Publisher | |
| ActivisionAU | Publisher | |
| ActivisionEU | Publisher | |
| ActivisionEU,NA | Publisher | |
| ActivisionJP | Publisher | |
| ActivisionJP,PAL | Publisher | |
| ActivisionNA | Publisher | |
| ActivisionNA, PAL | Publisher | |
| ActivisionNA,PAL | Publisher | |
| ActivisionPAL | Publisher | |
| ActivisionPAL,NA | Publisher | |
| Activison | Developer | |
| Actoon Studio | DeveloperPublisher | |
| Actos Games | DeveloperPublisher | |
| Actoz Soft | DeveloperPublisher | |
| Acttil | DeveloperPublisher | |
| Actual Humans | Developer | |
| Actualize | Publisher | |
| Actually The Moon | Developer | |
| Actura Software | DeveloperPublisher | |
| Acumen Software | Publisher | |
| Ada Interactive | Developer | |
| Ada Rook | Developer | |
| Adafheyesh | Developer | |
| Adagio Games | Developer | |
| Adam | Developer | |
| Adam TideGear Milecki | Developer | |
| Adam Carriere (Pyjama Bottom Studios) | Developer | |
| Adam Clarke | Developer | |
| Adam Dixon | Developer | |
| Adam Foster | DeveloperPublisher | |
| Adam Freeman | Developer | |
| Adam Kehl | Developer | |
| Adam L. | Developer | |
| Adam Le Doux | Developer | |
| Adam Moore | Developer | |
| Adam Parker | Developer | |
| Adam Pedersen | Developer | |
| Adam Proctor | Developer | |
| Adam Roy | Developer | |
| Adam Saltsman | Developer | |
| Adam Silverstein | Developer | |
| Adam Stanchos | Developer | |
| Adam Tool | Developer | |
| Adam Waind | Developer | |
| Adam Waring | Developer | |
| Adam Weesner | Developer | |
| Adam Wom | Developer | |
| AdamAlexandr | Developer | |
| AdamBridge | Developer | |
| AdamGCurtis | Developer | |
| AdamKruschwitz | Developer | |
| AdamMahdi | Developer | |
| AdamMizell | Developer | |
| AdamMtts | Developer | |
| AdamStrange | Developer | |
| AdamZachoval | Developer | |
| Adamgryu | Developer | |
| AddaLine | Developer | |
| Addictive 247 Games | Developer | |
| Addictive Games | DeveloperPublisher | |
| Addictive Software | Publisher | |
| Addison-Wesley | Publisher | |
| Addison-Wesley Publishing Company | Publisher | |
| Addix Software | Developer | |
| AddoPlayz | Developer | |
| Adebreg | Developer | |
| Adeel_D | Developer | |
| AdelFaure | Developer | |
| Adela Kapuścińska | Developer | |
| Adeline | Developer | |
| Adeline Software | Developer | |
| Adeline Software International | Developer | |
| Aden | Developer | |
| Aden Webb | Developer | |
| Adept Software | Developer | |
| Adept Studios | Developer | |
| Adesi | Developer | |
| Adglobe | Developer | |
| Adham Yehia | Developer | |
| Adhiesc | Developer | |
| Adi Robertson | Developer | |
| Adilla Gustiarani | Developer | |
| Adish (Dead Brain Studio) | Developer | |
| Aditya Chaudhary | Developer | |
| Aditya Sinha | Developer | |
| Aditya14 | Developer | |
| AdityaSahu | Developer | |
| AdityarajsinhGohil | Developer | |
| Admiral Software | Developer | |
| AdmiralEnto | Developer | |
| AdmiralSkye | Developer | |
| AdmiralSlowpoke | Developer | |
| Adnan Yousuf | Developer | |
| Adolfo Sakata | Developer | |
| Adonas | Developer | |
| Adoné | Developer | |
| Adore | Developer | |
| Adoxographist | Developer | |
| Adrenalin | Developer | |
| Adrenalin Entertainment | Developer | |
| Adrenalin Interactive | DeveloperPublisher | |
| Adrenium Games | Developer | |
| Adrenlin Entertainment | Developer | |
| Adri | Developer | |
| Adri888 | Developer | |
| Adria Martinez | Developer | |
| Adriaan de Jongh | DeveloperPublisher | |
| Adrian | Developer | |
| Adrian B. Danieli | Developer | |
| Adrian Bland | Developer | |
| Adrian Carless | Developer | |
| Adrian Forest | Developer | |
| Adrian Lazar | Developer | |
| Adrian Longland | Developer | |
| Adrian Ludley | Developer | |
| Adrian Miasik | Developer | |
| Adrian Pereiro | Developer | |
| Adrian Sherwin | Developer | |
| Adrian Sugden | Developer | |
| Adrian Zingg | Developer | |
| AdrianGenerator | Developer | |
| AdrianManser | Developer | |
| Adrianihle | Developer | |
| Adrianks47 | Developer | |