| AdPro | West Flanders |
| Adsys | |
| Advensys | |
| Advodata | |
| Aelin Therapeutics | |
| Aexis | Flemish Brabant |
| Affordable Solutions | Hainaut |
| Afriwise N.V. | |
| AGConsult | East Flanders |
| Agence du numérique S.A. | Namur |
| AGePe Logistics Software | |
| Agfa-Gevaert Group | Antwerp |
| Agomab Therapeutics | |
| AgroVision | East Flanders |
| Ahead IT B.V. | East Flanders |
| AI Planet | |
| Aigon | Brussels-Capital |
| Aikido Security B.V. | |
| Aion Bank | Brussels-Capital |
| AIOTI | Brussels-Capital |
| AiVidens | |
| Ajouta B.V. | Antwerp |
| Akimedia | Walloon Brabant |
| Akka Technologies | |
| Akretio | Walloon Brabant |
| Akti | East Flanders |
| Aktiv Consulting | |
| Alandra | Flemish Brabant |
| Albox N.V. | |
| Alchimerys sprl | Brussels-Capital |
| Alfa Solutions | |
| Alfa Systems N.V. | Antwerp |
| Alfahost.be | Antwerp |
| AlfaNet B.V. | Limburg |
| Algorithme Services en informatique | Liège |
| AliasSoftware | Hainaut |
| Alinoa | Brussels-Capital |
| All Digital | Brussels-Capital |
| All In One Systems B.V.B.A. | East Flanders |
| all2all | Brussels-Capital |
| all2all | |
| all2all - Moving Art Studio a.s.b.l. | Brussels-Capital |
| Allegro | |
| Allegro software Belgium N.V. | Walloon Brabant |
| Allied for Startups | Brussels-Capital |
| ALLOcloud | |
| Allrounders Webdesign | Antwerp |
| AllThingsTalk N.V. | |
| AlmightyDomains | East Flanders |
| Alpha Electronics Europe S.A. | Walloon Brabant |