| A.C.R.O.N.Y.M. Games |
| A2M (Artificial Mind) |
| Absolutist |
| Access Games |
| Acclaim |
| Acclaim Studios |
| ACES Studio |
| AceTeam |
| ACONY |
| Action Forms Ltd. |
| ACTive Gaming |
| Activision |
| Activision Blizzard |
| Activision Value |
| Adrenium Games |
| Adult Swim Games |
| AGEOD |
| Agetec |
| AI Factory |
| AIA USA |
| AiLive |
| Airtight Games |
| Akella |
| Aksys Games |
| Almost Human LTD |
| AlphaDream |
| Altar Games |
| Altron |
| Amaze Entertainment |
| Amusement Visions |
| Amuze |
| Anchor |
| Angel Studios |
| Anim-X |
| Antagonist |
| Apeiron |
| Appaloosa Interactive |
| AQ Interactive |
| Aquaplus |
| Arberth Studios |
| ARC Entertainment |
| Arc System Works |
| Arcade Moon |
| ArenaNet |
| Argonaut |
| Arkane Studios |
| Arkedo Studio |
| Armature Games |
| Artech Studios |
| Artematica Digital Arts |
| ArtePiazza |
| Artificial Mind and Movement |
| Artificial Studios |
| Artoon |
| ARUSH Entertainment |
| Arxel Tribe |
| Arzest |
| Ascaron |
| Asobo Studio |
| Aspyr |
